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LOGO

2021 Aon Proxy Statement

Table of Contents


Proxy Summary			1

Proposal 1—Election of Directors			8
Director Nominee Bios			10
Corporate Governance			16
Security Ownership of Directors and Executive Officers			23
Principal Holdings of Voting Securities			24

Proposal 2—Advisory Resolution on Executive Compensation			25
Compensation Committee Report			26
Compensation Discussion and Analysis			27
Executive Compensation			41

Report of the Audit Committee			62

Proposal 3–Resolution to Ratify the Appointment of Independent Registered Public Accounting Firm			64

Proposal 4—Re-appointment of Ernst & Young Chartered Accountants as the Company’s Statutory Auditor Under Irish Law			65

Proposal 5—Authorization of the Board or the Audit Committee of the Board to Determine the Remuneration of the Company’s Statutory Auditor’s Under Irish Law			65

Proposal 6—Resolution to Amend Article 190 of the Company’s Articles of Association			66

Proposal 7—Resolution to Authorize the Board to Capitalize Certain of the Company’s Non-distributable Reserves			66

Proposal 8—Resolution to Create Distributable Profits by the Reduction and Cancellation of the Amounts Capitalized Pursuant to the Authority Given Under Proposal 7			68

Other Information			70

Questions and Answers About the 2021 Annual General Meeting and Voting			73

Appendices			A-1

Notice of Annual General Meeting of Shareholders

Wednesday, June 2, 2021

8:30 a.m. Central Daylight Time

200 East Randolph Street

Chicago, Illinois

United States of America

Items of Business:

1.	By separate resolutions, to re-elect the 12 director nominees described in the proxy statement.

2.	To approve by an advisory resolution the compensation of the Company’s named executive officers.

3.	To ratify the appointment of Ernst & Young LLP as the Company’s independent registered public accounting firm (“Ernst & Young US”) for the fiscal year ending December 31, 2021.

4.	To re-appoint Ernst & Young Chartered Accountants as the Company’s statutory auditor under Irish law (“Ernst & Young Ireland”), to hold office until the conclusion of the Company’s next annual general meeting.

5.	To authorize the Board or the Audit Committee of the Board to determine the remuneration of Ernst & Young Ireland, in its capacity as the Company’s statutory auditor under Irish law.

6.	To amend Article 190 of the Company’s Articles of Association.

7.	To authorize the Board to capitalize certain of the Company’s non-distributable reserves.

8.	To approve the creation of distributable profits by the reduction and cancellation of the amounts capitalized pursuant to the authority given under Proposal 7.

In light of the ongoing COVID-19 pandemic, shareholders are strongly encouraged to vote their shares by proxy in advance of the Annual General Meeting (the “Annual Meeting”). Shareholders who wish to attend the Annual Meeting virtually may do so via webcast at www.meetingcenter.io/207459271; password: AON2021, as further described on page 75 of the proxy statement. Note that attending the Annual Meeting virtually will not allow you to vote at the Annual Meeting. Accordingly, we strongly advise you to vote in advance by one of the methods described on page 73 of the Proxy Statement.

During the Annual Meeting, the Board will present, for consideration by the shareholders, the Company’s statutory financial statements under Irish law for the fiscal year ended December 31, 2020 (including the reports of the directors and the Irish statutory auditor thereon) and a review of the Company’s affairs. We urge you to read the attached proxy statement for additional information concerning the matters to be considered at the Annual Meeting. The proxy statement shall be deemed incorporated into this notice.

Holders of Class A Ordinary Shares at the close of business on April 8, 2021 can vote at the Annual Meeting. A shareholder of record entitled to attend and vote at the Annual Meeting may appoint one or more proxies to attend, speak and vote on his or her behalf by any of the procedures set out below and on page 73 of the proxy statement. A proxy holder need not be a shareholder of record. To be valid a proxy must be received by the Company using one of such procedures no later than 11:59 pm EDT on June 1, 2021, the proxy deadline.

By Order of the Board of Directors,

LOGO

Darren Zeidel

Company Secretary

April 15, 2021

Your vote is important

Only holders of Class A Ordinary Shares as of the record date April 8, 2021 can vote at the Annual Meeting. Please cast your vote as soon as possible in one of the following ways:


Internet Online at www.envisionreports.com/AON and follow the instructions on your proxy card or notice of internet availability

Telephone Call 1-800-652-VOTE (8683)

Mail Mark, sign and date your proxy card or voting instruction form and return it in the postage-paid envelope

The proxy statement, our Annual Report for the fiscal year ended December 31, 2020 and our Irish financial statements are available at www.envisionreports.com/AON. This notice and proxy statement is being mailed or made available to shareholders on or about April 15, 2021.

Proxy Summary

Voting Matters

Shareholders are being asked to vote on the following matters at the Annual Meeting:


		Our Board’s Recommendation
Proposal 1. Resolutions Regarding the Re-election of Directors (page 8) The 12 nominees possess the necessary qualifications and diversity of perspectives to provide effective oversight of the Company.		FOR each nominee
Proposal 2. Advisory Resolution on Executive Compensation (page 25) The Company seeks a non-binding advisory vote to approve the compensation of its named executive officers. The Board values shareholders’ opinions, and the Organization and Compensation Committee will take into account the outcome of the advisory vote when considering future executive compensation.		FOR
Proposal 3. Resolution to Ratify the Appointment of Independent Registered Public Accounting Firm (page 64) The Board believes that the continued retention of Ernst & Young US to serve as our independent registered accounting firm is in the best interests of the Company and its shareholders.		FOR
Proposal 4. Resolution to Re-Appoint Ernst & Young Ireland as the Company’s Statutory Auditor Under Irish law (page 65) The Board believes that the continued retention of Ernst & Young Ireland to serve as our statutory auditor under Irish law from the conclusion of the Annual Meeting until the conclusion of the next annual general meeting of the Company is in the best interests of the Company and its shareholders.		FOR
Proposal 5. Resolution to Authorize the Board or the Audit Committee of the Board to Determine the Remuneration of the Company’s Statutory Auditor Under Irish Law (page 65) We are asking our shareholders to authorize the Board or the Audit Committee to determine Ernst & Young Ireland’s remuneration as our statutory auditor under Irish law.		FOR
Proposal 6. Resolution to Amend Article 190 of the Company’s Articles of Association (page 66) We are asking our shareholders to approve certain amendments to Article 190 of the Company’s Articles of Association, to enable the Board, subject to receipt of shareholders’ authorization pursuant to Proposal 7, to capitalize up to the entire amount standing to the credit of the Company’s merger reserve and unrealized revaluation reserve in the manner contemplated by Proposal 7.		FOR
Proposal 7. Resolution to Authorize the Board to Capitalize Certain of the Company’s Non-distributable Reserves (page 66) We are asking our shareholders, conditional on the approval of Proposal 6, to authorize the Board to capitalize up to the entire amount standing to the credit of the Company’s merger reserve and unrealized revaluation reserve which capitalized amount can subsequently be reduced and cancelled pursuant to Proposal 8, and be treated as distributable profits which can be used to pay dividends and effect share repurchases and redemptions.		FOR
Proposal 8. Resolution to Approve the Creation of Distributable Profits by the Reduction and Cancellation of the Amounts Capitalized Pursuant to the Authority Given Under Proposal 7 (page 68) We are asking our shareholders to approve the creation of distributable profits, by the reduction and cancellation of up to the entire amount capitalized by the Board pursuant to the authority granted by the shareholders pursuant to Proposal 7. The amount reduced and cancelled will be treated as distributable profits which can be used to pay dividends and effect share repurchases and redemptions.		FOR

2021 Aon Proxy Statement 1

Our Company and 2020 Highlights

Aon is a leading global professional services firm providing

advice and solutions in Risk, Retirement and Health at a

time when those topics have never been more important to

the global economy. Aon develops insights that reduce the

volatility our clients face and help them maximize their

performance.

In 2020, we delivered positive performance across each of our key metrics amidst challenging macroeconomic conditions. We returned approximately $2.2 billion of capital to shareholders through share repurchases and dividends, highlighting our strong cash flow generation and effective allocation of capital.

In assessing our performance, we focus on four metrics that are not recognized under U.S. generally accepted accounting principles (“GAAP”) that we communicate to shareholders: organic growth, expansion of adjusted operating margins, increase in adjusted diluted earnings per share and increased free cash flow. These non-GAAP metrics should be viewed in addition to, not instead of, our consolidated financial statements and notes thereto. A reconciliation of these non-GAAP metrics to the most directly comparable GAAP metrics is set forth in Appendix A to this proxy statement.

“We delivered a strong finish to 2020, demonstrating the stability of our business and the efficiency of our Aon Business Services platform. Our team is incredibly proud of the tremendous resiliency demonstrated by our colleagues. We enter 2021 in a position of strength, with momentum for Aon and our pending combination with Willis Towers Watson.”

Greg Case, CEO

The following is our measure of 2020 performance against GAAP metrics, as well as the four non-GAAP metrics outlined above:

•

Total revenue growth was flat and organic revenue growth was 1%, reflecting strength in the core portions of our business, partially offset by a decline in the more discretionary portions

•

25.1% Operating Margin; 28.5% Adjusted Operating Margin

•

$8.45 Earnings Per Share; $9.81 Adjusted Diluted Earnings

•

$2,783 million Cash Flow from Operations; $2,642 million Free Cash Flow

2 2021 Aon Proxy Statement

Combination with Willis Towers Watson

In March 2020, we entered into a business combination agreement with Willis Towers Watson, which will bring together 95,000 colleagues in risk, retirement and health, going to market under the Aon brand. On August 26, 2020, Aon and Willis Towers Watson shareholders voted overwhelmingly to approve the combination. Since our March 2020 announcement, our conviction in the combination and confidence in the talent from both companies has only increased.

In January 2021, we announced the combined executive committee that will be in place once the combination is closed. This team embraces the aspiration of creating a “one firm” mindset and brings together the best expertise, talent, and leadership from both organizations. This combination of Aon and Willis Towers Watson will allow the combined firm to harness complementary technologies, data and leading decision science capabilities to develop solutions at a pace not previously possible. Our future combined firm will help our clients meet rapidly changing, increasingly complex and interconnected challenges.

The combination of Aon with Willis Towers Watson represents a bold step that we believe will enable our colleagues to establish a new standard of client leadership and innovation.

Board Composition and Skills

LOGO

2021 Aon Proxy Statement 3

Board Oversight, COVID-19 and

Inclusion & Diversity

2020 was an unprecedented year for all. Given the magnitude of uncertainty around the COVID-19 pandemic, our Board actively worked with management to assess the impact of the pandemic on our business operations, our colleagues and our clients and provided advice and oversight to management toward the development of short- and long-term strategies to mitigate associated risks. Our Board and each of its committees continuously engaged on the evolving challenges—including optimizing financial flexibility and resiliency, technology enhancements and security, colleague physical and mental health, return to office planning and global compliance—throughout the year, receiving regular updates from management. For more on our Board’s approach to risk oversight, please see page 16 of this proxy statement.

In 2020, we shifted the vast majority of our colleagues to remote work in response to the COVID-19 pandemic. The historic steps we’ve taken to build our Aon Business Services platform were instrumental in our response. Acting early, we began offering tools and services for enabling remote work and avoiding disruption in client service while emphasizing our commitment to colleague health and well-being. Our programs and policies on flexible work,

leadership development, learning, telemedicine, childcare, sick leave and social and emotional health rapidly evolved to meet the new challenges and create a “new better” for our colleagues based on where they live and work.

Our colleagues are the cornerstone of Aon’s success, and a diverse and inclusive workforce is a business imperative and key to Aon’s long-term success. In 2020, Aon earned top rankings in the Human Rights Campaign’s Corporate Equality Index, our CEO Greg Case was named the top ally on the Involve OUTstanding LGBT+ Ally Executive list, and we committed to expand Aon’s Apprenticeship program, designed to bridge the gap between education and employment. The commitment to inclusion and diversity starts at the top with our Board, and in 2020, our Board formed the Inclusion & Diversity Sub-Committee, chaired by our Board Chair Lester Knight. This step helps place inclusion and diversity at the forefront for management and our Board, for the betterment of our colleagues, our clients and the communities where we work and live. For more on the responsibilities of the Inclusion & Diversity Sub-Committee, please see page 19 of this proxy statement.

4 2021 Aon Proxy Statement

Director Nominees



Name	Age	Director Since	Committee Membership	Other Boards^†
Lester B. Knight, Chair*	62	1999	Executive Committee - Chair Governance/Nominating Committee - Chair Inclusion & Diversity Sub-Committee - Chair	—
Gregory C. Case, CEO	58	2005	Executive Committee Inclusion & Diversity Sub-Committee	1
Jin-Yong Cai*	61	2016	Finance Committee Organization and Compensation Committee	1
Jeffrey C. Campbell*	60	2018	Audit Committee Organization and Compensation Committee	1
Fulvio Conti*	73	2008	Audit Committee Executive Committee Finance Committee - Chair Governance/Nominating Committee	1
Cheryl A. Francis*	67	2010	Finance Committee Organization and Compensation Committee	2
J. Michael Losh*	74	2003	Audit Committee - Chair Executive Committee Finance Committee Governance/Nominating Committee	3
Richard B. Myers*	79	2006	Audit Committee Compliance Sub-Committee Organization and Compensation Committee	1
Richard C. Notebaert*	73	1998	Executive Committee Finance Committee Governance/Nominating Committee Inclusion & Diversity Sub-Committee Organization and Compensation Committee - Chair	1
Gloria Santona*	70	2004	Audit Committee Compliance Sub-Committee - Chair Governance/Nominating Committee Inclusion & Diversity Sub-Committee	—
Byron O. Spruell*	56	2020	Audit Committee Governance/Nominating Committee	—
Carolyn Y. Woo*	67	1998	Audit Committee Compliance Sub-Committee Organization and Compensation Committee	1

* Independent Director

^† Number of other public company boards

2021 Aon Proxy Statement 5

Corporate Governance Highlights

Aon’s commitment to good corporate governance is integral to our business. Highlights of our strong corporate governance practices include:



Annual election of directors	Separation of Board Chair and CEO	Strong Board oversight of risk management programs

11 of 12 directors are independent	Directors elected by a majority of votes cast in an uncontested election	Formation of Inclusion & Diversity Sub-Committee

Regular executive sessions of the Board and its committees	Shareholder ability to call a special meeting	Robust share ownership guidelines for directors and senior executives

2020 Executive Compensation Highlights

Leadership Performance Program. For each of our NEOs, the majority of his or her target compensation opportunity awarded in 2020 consisted of a long-term, performance-based grant under our Leadership Performance Program (“LPP”). In early 2021, we settled performance share units granted to our NEOs in 2018 under our thirteenth LPP cycle (“LPP 13”). The settlement of those units in Class A Ordinary Shares was contingent upon achieving adjusted earnings per share of at least $20.68 (threshold performance) over the performance period from January 1, 2018 to December 31, 2020, and reflects achievement of adjusted earnings per share of $22.36 (after permitted adjustments), which exceeded the target earnings per share of $21.47. Also in 2020, we granted performance share units under our fifteenth LPP cycle (“LPP 15”) to each of our NEOs, which are expected to be settled in 2023 contingent upon the Company’s adjusted earnings per share performance over the January 1, 2020 to December 31, 2022 performance period.

Annual Incentive Compensation. Annual incentive bonuses paid to our NEOs reflected our application of the incentive pool funding guidelines adopted by the Organization and Compensation Committee of the Board (the “Compensation Committee”) that are based on a comparison of current year adjusted operating income results against prior year results, as well as the Compensation Committee’s evaluation of each NEO’s contributions to our business and financial results, delivery of key strategic initiatives and personal leadership qualities. Once determined, annual incentives to our NEOs were paid 65% in the form of cash and 35% in the form of time-vested restricted share units in order to provide value to our executives that is tied to the long-term performance of the Company. Annual incentive bonuses for 2020 were paid to our NEOs in early 2021 following the Company’s achievement of adjusted operating income of $3,150 million. For purposes of determining the annual incentive award funding, the Compensation Committee adjusted this amount downward to $3,025 million to exclude $125 million of restructuring savings. The annual incentive awards are described in more detail in the section captioned “Compensation Discussion and Analysis” below.

6 2021 Aon Proxy Statement

Compensation-Related Best Practices

Our compensation philosophy and related governance features are complemented by several policies and practices designed to align our executive compensation program with the long-term interests of our shareholders, including the following:



Robust share ownership guidelines for executive officers and directors	Clawback policy in the event of financial restatements, fraud, or a material violation of Company policies	Annual say-on-pay vote for shareholders

Robust annual risk assessment of compensation programs, policies and practices	Independent compensation consultant advises the Compensation Committee	Prohibition on hedging transactions by all employees and directors; prohibition on pledging by executive officers and directors

LOGO

Pay for performance philosophy weighted towards variable at-risk performance-based compensation

LOGO

No dividends or dividend equivalents on unvested performance share awards

LOGO

Effective balance between differentiated short-term and long-term performance factors and incentives

2021 Aon Proxy Statement 7

Proposal 1–Resolutions Regarding the

Re-Election of Directors

The Board of Directors unanimously recommends that shareholders vote “FOR” each nominee to serve as director.

What am I voting on?

The 12 current members of the Board are standing for re-election, in each case to serve until our 2022 annual meeting.

The Governance/Nominating Committee of the Board (the “Governance/Nominating Committee”) has recommended to the Board that each director be nominated. With respect to Mr. Case, his employment agreement provides that he will be nominated for election as a director at each annual meeting of shareholders during the period of his employment. All nominees for director have consented to being named in this proxy statement named and have agreed to serve as directors if re-elected. We have no reason to believe that any of the nominees will not be available to serve as a director. However, if any nominee should become unavailable to serve for any reason, the proxies may be voted for such substitute nominees as may be designated by the Board.

The term of each director expires at the next annual general meeting of shareholders, and each director will continue in office until the election of his or her respective successor or until his or her resignation or removal in accordance with the Company’s articles of association (the “Articles”) or the Irish Companies Act 2014, as amended (the “Irish Companies Act”). Consistent with the terms of the Articles, the Board currently is authorized to have up to 21 members, and the number of directors was most recently set by the Board at 12.

Each of the 12 nominees for director will be elected by the vote of a majority of the votes cast with respect to such nominee. A shareholder may: (i) vote for the election of a nominee; (ii) vote against the election of a nominee; or (iii) abstain from voting for a nominee. Unless a proxy contains instructions to the contrary, it is assumed that the proxy will be voted “FOR” the re-election of each nominee named on the following pages.

The form of shareholder resolution for this proposal is below:

RESOLVED THAT, the following individuals be, and each hereby is, by way of separate ordinary resolution, re-elected to serve as director until the election of his or her respective successor or until his or her earlier removal or resignation pursuant to the Articles:


Lester B. Knight		J. Michael Losh
Jeffrey C. Campbell		Richard B. Myers
Gregory C. Case		Richard C. Notebaert
Jin-Yong Cai		Gloria Santona
Fulvio Conti		Byron O. Spruell
Cheryl A. Francis		Carolyn Y. Woo

Aon values a number of attributes and criteria when identifying nominees to serve as a director, including professional background, expertise, reputation for integrity, business, financial and management experience, leadership capabilities and diversity. We believe all of the nominees are individuals with a reputation for integrity, demonstrate strong leadership capabilities and are able to work collaboratively to make contributions to the Board and management.

Willis Towers Watson Combination

Our business combination agreement with Willis Towers Watson (“WTW”) was approved by Aon and WTW shareholders on August 26, 2020. As described in the definitive joint proxy statement, dated July 8, 2020, the agreement provides that, at the effective time of the combination, four members of the Board will resign and four individuals from the WTW board of directors, designated by WTW and including WTW’s Chief Executive Officer, will become directors of Aon. This proxy statement (and the accompanying proxy card) assumes that the combination will become effective after the date of the Annual Meeting. Accordingly, you are being asked to vote on the re-election of the 12 current members of the Board.

However, in the event that the combination were to become effective prior to the date of the Annual Meeting: (i) at the effective time of the combination, the Board would accept the resignations of four members of the Board (each of whom will confirm the withdrawal of his or her candidacy at the Annual Meeting); (ii) at the Annual Meeting, the ordinary resolutions relating to the re-election of such four directors who would have resigned will be adjourned indefinitely; and (iii) at the

8 2021 Aon Proxy Statement

effective time of the combination, the Board would appoint four individuals from the WTW board of directors, designated by WTW and including WTW’s Chief Executive Officer, as new members of the Board, to serve until our 2022 annual meeting of shareholders. The four new members of the Board would not be subject to re-election at the Annual Meeting.

As of the date of this proxy statement, the resigning and new directors have not yet been determined. However, within four business days of such resignations and appointments and prior to the Annual Meeting, we would file a Form 8-K identifying the four resigning directors and providing the biographies, committee membership, independence determinations and other required information regarding the four newly appointed members of the Board.

2021 Aon Proxy Statement 9

Director Nominee Bios


Lester B. Knight Director since 1999 Age: 62 Committees: • Executive Committee (Chair) • Governance/Nominating Committee (Chair) • Inclusion & Diversity Sub-Committee (Chair)		Mr. Knight is a Founding Partner of RoundTable Healthcare Partners and the former Vice Chairman and a director of Cardinal Health, Inc., a diversified healthcare service company. Mr. Knight was Chairman of the Board and Chief Executive Officer of Allegiance Corporation from 1996 until February 1999, and had been with Baxter International, Inc. from 1981 until 1996, where he served as Corporate Vice President from 1990, Executive Vice President from 1992 and as a director from 1995. Mr. Knight became Chairman of the Board of Directors of Aon in August 2008. He is a life director of NorthShore University HealthSystem and Junior Achievement of Chicago, a life Trustee of Northwestern University and a member of the Civic Committee of The Commercial Club of Chicago. Skills & Qualifications: Mr. Knight’s experience as the founder of a private equity firm focused on investing in the healthcare industry, his executive background at several leading healthcare companies, and his financial and investment experience provides the Board with executive leadership and oversight experience. Mr. Knight provides valuable perspectives with his broad experience in corporate governance, strategic transactions, business transformation and growth and oversight.
Gregory C. Case Director since 2005 Age: 58 Committees: • Executive Committee • Inclusion & Diversity Sub-Committee		Mr. Case has served as Chief Executive Officer and director of Aon since April 2005. He also served as President from 2005 to 2018. Prior to joining Aon, Mr. Case was with McKinsey & Company, the global management consulting firm, for 17 years where he served on the governing Shareholders’ Council and as head of the Global Insurance and Financial Services practice. Prior to joining McKinsey, Mr. Case was with the investment banking firm of Piper, Jaffray and Hopwood and the Federal Reserve Bank of Kansas City. Mr. Case is a director of Discover Financial Services. Skills & Qualifications: As Chief Executive Officer of Aon, Mr. Case brings to the Board his day-to-day experiences leading Aon’s 50,000 colleagues in 120 countries and his intimate knowledge of Aon’s business and operations. Mr. Case’s background as a management consultant, including in the global insurance and financial services areas, bring critical industry perspective to the Board.
Jin-Yong Cai Director since 2016 Age: 61 Committees: • Finance Committee • Organization and Compensation Committee		Mr. Cai is a Partner at Global Infrastructure Partners, a global private equity investment firm. Prior to his current position, Mr. Cai was a Partner at TPG Capital, L.P., a global private equity investment firm. From 2012 to 2016, Mr. Cai was the Chief Executive Officer of the International Finance Corporation, a member of the World Bank Group and the largest global development institution focused on private sector development. Before the International Finance Corporation, Mr. Cai worked in the financial services industry for nearly two decades, including 12 years with Goldman Sachs Group, as a Partner and its top executive in China. He began his career at the World Bank Group. Mr. Cai is a director of PetroChina Company Limited. Skills & Qualifications: Mr. Cai’s experience in global finance and international business, particularly in the Asia-Pacific region enhance the Board’s global perspectives. Mr. Cai’s increased level of financial literacy and extensive background with international finance and global management provide valuable perspective and knowledge relating to financial risk and risks related to the Company’s international activities and growth strategies.

10 2021 Aon Proxy Statement

Jeffrey C. Campbell

Director since 2018

Age: 60

Committees:

• Audit Committee

• Organization and Compensation Committee

Mr. Campbell is currently the Executive Vice President and Chief Financial Officer at American Express, a position he has held since July 2013. From 2004 to 2013, Mr. Campbell served as the Executive Vice President and Chief Financial Officer at McKesson Corporation. Prior to his time at McKesson Corporation, Mr. Campbell spent 13 years at AMR Corporation and its principal subsidiary, American Airlines, ultimately becoming its Chief Financial Officer in 2002. He serves as the Lead Director and Chair of the Audit Committee of Hexcel Corporation.

Skills & Qualifications: Having served as chief financial officer of three multinational, publicly traded companies, Mr. Campbell adds financial expertise and risk management leadership to the Board. His significant business experience, deep financial acumen and leadership in the development of diverse talent provide the Board and its committees with valuable management perspective, as well as knowledge and experience relating to the financial services sector. This experience has also led the Board to determine that Mr. Campbell is an “audit committee financial expert” as defined by the Securities and Exchange Commission (the “SEC”).

Fulvio Conti

Director since 2008

Age: 73

Committees:

• Finance Committee (Chair)

• Audit Committee

• Executive Committee

• Governance/Nominating Committee

Mr. Conti served as Chairman of TIM SpA, a leader in the telecommunications market from May 2018 to September 2019. He served as Chief Executive Officer and General Manager of Enel SpA, Italy’s largest power company, from May 2005 to May 2014. From 1999 until 2005, he served as Chief Financial Officer of Enel. Mr. Conti has a financial and industrial career spanning over 40 years. From 1970 to 1990, he held many roles at Mobil Oil Corporation in Italy and other countries, including as Chief Financial Officer and general manager of Mobil Oil Europe and Chief Operating Officer of Mobil Plastics Europe. From 1991 to 1995, Mr. Conti was Chief Financial Officer of Montedison-Compart, SpA. Prior to joining Enel, SpA, he was the Chief Financial Officer and general manager of Ferrovie dello Stato SpA and Telecom Italia SpA. Mr. Conti currently serves as Chairman of Innova Italy Srl, Chairman of SGI SpA (Societa’ Gasdotti ltatlia SpA), chairman of Fondo Italiano Efficienza Energetica (FIEE SGR SpA), director of Unidad Editorial SA, and director of RBC PSJC. Mr. Conti previously served as a non-executive director of Barclays plc, RCS Mediagroup and director of the Italian Institute of Technology. Mr. Conti served as a director of the National Academy of Santa Cecilia stepping down from his position in 2014. In 2009, he was appointed “Cavaliere del Lavoro” of the Italian Republic and in December of that year he became “Officier de la Légion d’Honneur” of the French Republic.

Skills & Qualifications: Mr. Conti’s background as a chief executive officer and chief financial officer of a large international energy company, his familiarity with international business and finance activities, particularly in the European Union, and his global financial and management experience bring financial expertise and global leadership to the Board. In addition, Mr. Conti’s background as a chief financial officer of a multinational utility provides a knowledgeable resource on matters relating to financial reporting and treasury. His experience has also led the Board to determine that Mr. Conti is an “audit committee financial expert” as defined by the SEC.

2021 Aon Proxy Statement 11

Cheryl A. Francis

Director since 2010

Age: 67

Committees:

• Finance Committee

• Organization and Compensation Committee

Ms. Francis served as Executive Vice President and Chief Financial Officer of R.R. Donnelley & Sons Co., a publicly traded print media company, from 1995 until 2000. Since 2000, Ms. Francis has served as a business consultant and, since August 2008, as Co-Chair of the Corporate Leadership Center. From 2002 until August 2008, she served as Vice Chairman of the Corporate Leadership Center. Prior to her role at R.R. Donnelley, Ms. Francis served on the management team of FMC Corporation and its subsidiary, FMC Gold, including serving as Chief Financial Officer of FMC Gold from 1987 through 1991, and Treasurer of FMC Corporation from 1993 through 1995. She was also an adjunct professor for the University of Chicago Graduate School of Business from 1991 through 1993. Ms. Francis currently serves as a director of HNI Corporation and Morningstar, Inc., and previously served as a director of Hewitt Associates, Inc. from 2002 until our acquisition of Hewitt Associates, Inc. in 2010.

Skills & Qualifications: Ms. Francis’s background as a chief financial officer of a large publicly traded company provides the Board with an increased level of financial literacy. In addition, her role as a Board member of other public companies provides valuable perspective on matters of risk oversight, corporate governance and strategy. As Co-Founder of the Corporate Leadership Center’s CEO Perspectives and Leading Women Executives, Ms. Francis is a leading voice on diversity and leadership development.

J. Michael Losh

Director since 2003

Age: 74

Committees:

• Audit Committee (Chair)

• Executive Committee

• Finance Committee

• Governance/Nominating Committee

From July 2004 to May 2005, Mr. Losh served as Interim Chief Financial Officer of Cardinal Health, Inc., a diversified healthcare service company. From 1994 until 2000, Mr. Losh served as Chief Financial Officer and Executive Vice President of General Motors Corporation. Mr. Losh spent 36 years in various capacities with General Motors, where he served as Chairman of GMAC, its financial services group, Group Vice President of North American Sales, Service and Marketing, and Vice President and General Manager of both its Oldsmobile Division and Pontiac Division. Mr. Losh currently serves as a director of Cardinal Health, Inc., Masco Corp., where he serves as non-executive chairman, and Amesite, Inc. He previously served as a director of H.B. Fuller Corporation, CareFusion Corporation, and Prologis, Inc.

Skills & Qualifications: Mr. Losh’s background as a chief financial officer of a large international automobile manufacturing company and a healthcare company provides the Board with an increased level of financial literacy. In addition, his role as a board member of a variety of companies provides valuable perspective on matters of risk oversight, corporate governance and executive management. Mr. Losh’s experience has also led the Board to determine that Mr. Losh is an “audit committee financial expert” as defined by the SEC.

12 2021 Aon Proxy Statement

Richard B. Myers

Director since 2006

Age: 79

Committees:

• Audit Committee

• Compliance Sub- Committee

• Organization and Compensation Committee

General Myers is the President of Kansas State University. He previously served as the fifteenth Chairman of the Joint Chiefs of Staff from October 1, 2001 until his retirement on September 30, 2005. In this capacity, he was the highest-ranking officer in the United States military and served as the principal military advisor to the President, the Secretary of Defense and the National Security Council. Prior to becoming Chairman, General Myers served as Vice Chairman of the Joint Chiefs of Staff from March 2000 to September 2001. From August 1998 to February 2000, General Myers was Commander in Chief, North American Aerospace Defense Command and U.S. Space Command; Commander, Air Force Space Command; and Department of Defense manager, space transportation system contingency support at Peterson Air Force Base, Colorado. Prior to serving in these roles, he was Commander, Pacific Air Forces, Hickam Air Force Base, Hawaii, from July 1997 to July 1998. General Myers previously served as a director of Deere & Company, Northrup Grumman Technologies, and United Technologies Corporation. General Myers previously served as the Colin L. Powell Chair of National Security, Leadership, Character, and Ethics at the National Defense University and was Chairman of the Board of Directors of the United Service Organization’s World Board of Governors. General Myers currently serves as a director of MP Materials.

Skills & Qualifications: General Myers’s background as the former Chairman of the Joint Chiefs of Staff, among other leadership positions outside of the private sector, bring diverse leadership experiences and consensus building skills to the Board. In addition, General Myers’s extensive experience and knowledge of global affairs provides the Board with an invaluable resource regarding conducting business in diverse geo-political environments.

Richard C. Notebaert

Director since 1998

Age: 73

Committees:

• Organization and Compensation Committee (Chair)

• Executive Committee

• Finance Committee

• Governance/Nominating Committee

• Inclusion & Diversity Sub-
Committee

From June 2002 until August 2007, Mr. Notebaert served as Chairman and Chief Executive Officer of Qwest Communications International Inc., a leading provider of broadband Internet-based data, voice and image communications. He previously served as President and Chief Executive Officer of Tellabs, Inc., which designs and markets equipment to providers of telecommunications services worldwide, from August 2000 to June 2002, and as a director of Tellabs from April 2000 to June 2002. He served as Chairman of the Board and Chief Executive Officer of Ameritech Corporation, a full-service communications company, from 1994 until 1999. Mr. Notebaert first joined Ameritech Communications in 1983 and served in significant positions within the Ameritech organization before his election as Vice Chairman in January 1993, President and Chief Operating Officer in June 1993 and President and Chief Executive Officer in January 1994. Mr. Notebaert is a director of American Electric Power and is a Trustee Emeritus of the Board of Trustees of the University of Notre Dame. Mr. Notebaert previously served as a director of Cardinal Health, Inc. and as Chairman of the Board of Trustees of the University of Notre Dame.

Skills & Qualifications: Mr. Notebaert’s background as a chairman and chief executive officer of several large international communications companies provides the Board with substantial management expertise, including in the areas of global operations, technology and innovation and strategic planning. In addition, Mr. Notebaert’s experience as a director of a variety of companies provides valuable perspective on matters of risk oversight, corporate governance and executive management.

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Gloria Santona

Director since 2004

Age: 70

Committees:

• Compliance Sub-Committee (Chair)

• Audit Committee

• Governance/Nominating Committee

• Inclusion & Diversity Sub-Committee

Ms. Santona is currently Of Counsel at Baker McKenzie, an international law firm. Ms. Santona served as Executive Vice President, General Counsel and Secretary of McDonald’s Corporation from 2001 to 2017 when she retired. Since joining McDonald’s in 1977, Ms. Santona held positions of increasing responsibility in the legal department, serving as U.S. General Counsel from December 1999 to June 2001 and corporate General Counsel since 2001. She is a member of the American Bar Association, the Association of General Counsel, the Society for Corporate Governance and the National Society of Corporate Directors. She is a former member of the Board of Directors of the American Society of Corporate Secretaries, the Association of Corporate Counsel and the Minority Corporate Counsel Association. She is also a member of the Board of Trustees of Rush University Medical Center and is a member of the Boards of Directors of the National Immigrant Justice Center. She is a former member of the Board of Trustees of the Chicago Zoological Society and the Chicago Symphony Orchestra and the Board of Directors of The Chicago Network and the Chicago Food Depository.

Skills & Qualifications: Ms. Santona’s legal background, including her experience serving as a general counsel and secretary of a large international corporation, brings critical perspective to the Board and enhances the Board’s global risk oversight capabilities. Ms. Santona’s diverse legal background contributes corporate governance, legal, regulatory and compliance expertise and further brings critical perspective on long-term growth strategy planning. Under Ms. Santona’s leadership, McDonald’s legal department won numerous awards for its commitment to diversity and pro bono.

Byron O. Spruell

Director since 2020

Age: 56

Committees:

• Audit Committee

• Governance/Nominating Committee

Mr. Spruell is the President of League Operations at the National Basketball Association, a position he has held since August 2016. Prior to joining the National Basketball Association, Mr. Spruell spent 20 years at Deloitte LLP, most recently as its Vice Chairman, Central Region Marketplace Leader and Chicago Managing Principal. He serves on several non-profit boards, including the University of Notre Dame Board of Trustees, the Museum of Science and Industry, Metropolitan Family Services in Chicago and the Jackie Robinson Foundation.

Skills & Qualifications: Mr. Spruell’s background in a professional services firm and as a current executive at the National Basketball Association provides the Board with valuable experience in operations management, agility, talent development, application of analytics and innovation, business continuity and colleague health and wellness. Mr. Spruell’s experiences at Deloitte LLP and as Chair of the Audit Committee of the University of Notre Dame’s Board of Trustees further elevates the Board’s financial and accounting expertise. Additionally, Mr. Spruell’s service on non-profit boards enhances the Board’s perspectives around community engagement and social impact.

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Carolyn Y. Woo

Director since 1998

Age: 67

Committees:

• Audit Committee

• Compliance Sub-
Committee

• Organization and Compensation Committee

Dr. Woo is the former President and Chief Executive Officer of Catholic Relief Services, a position she held from 2012 to 2016. From July 1997 to December 2011, Dr. Woo served as the Dean of the Mendoza College of Business at the University of Notre Dame. Dr. Woo currently serves on the Board of Directors of NiSource Industries, Inc. and Arabesque Partners.

Skills & Qualifications: Dr. Woo’s background as leader of a global relief organization provides the Board with an invaluable resource regarding conducting business in diverse geo-political environments. In addition, her previous position as former dean of the business school of a large university provides leadership expertise and consensus building skills, as well as relevant management and business experience. Dr. Woo’s longstanding commitments to social and educational organizations contributes critical perspectives to the Board on corporate social responsibility.

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Corporate Governance

We are committed to continually enhancing our corporate governance practices, which we believe help us sustain our success and build long-term value for our shareholders and other stakeholders. Aon’s Governance Guidelines provide the framework for our system of corporate governance, which, together with our committee charters and Code of Business Conduct, set forth standards of conduct for employees, officers and directors. The Board and its Committees provide oversight of Aon’s overall performance, strategic direction and executive management team performance, including management of the Company’s top risks and mitigation plans. The Board also reviews major initiatives and transactions and advises on key financial and business matters. The charter of each committee, the Governance Guidelines and the Code of Business Conduct are available on the corporate governance section of our website at http://www.aon.com/about-aon/corporate-governance/corporate-governance.jsp. For more information about our Board’s and management’s oversight of risk, including oversight of key environmental, social and governance (“ESG”) risks, please see “Board Role in Risk Oversight” below.


Corporate Governance Best Practices

		Board Independence. All of our directors are independent, with the exception of our Chief Executive Officer.

		Independent Chair. We have had an independent chair Board leadership structure since 2008.

		Formation of Inclusion & Diversity Sub-Committee. In 2020, the Board established the Inclusion & Diversity Sub-Committee of the Governance/Nominating Committee, to help ensure focused evaluation, oversight and management of the Aon’s inclusion and diversity strategies and initiatives.

		Annual Elections with Majority Voting. Directors are elected annually by a majority of votes cast in an uncontested election.

		Shareholder Right to Call a Special Meeting. Our shareholders owning 10% of our shares may request that the company call an extraordinary general meeting, in accordance with the requirements of the Irish Companies Act.

		Ongoing Director Refreshment. 25% of our directors have served on the Board for less than 5 years.

		Executive Sessions. Our independent directors meet regularly in executive sessions.

		Incentive Repayment Policy and Forfeiture Provision. Our Board has adopted an incentive repayment policy whereby the Board may cancel or require reimbursement of any cash-based incentive payments or equity-based awards received if the cash-based incentive payment or equity-based award was based on the achievement of financial results that are subsequently restated. In addition, beginning with equity-based awards granted in 2019, unvested equity-based awards are subject to forfeiture in the event of a material violation of the Company’s policies or procedures or a breach of applicable restrictive covenants.

		Prohibitions on Hedging and Pledging Company Shares. Our Board has adopted a policy prohibiting all employees and directors from engaging in short sales, publicly traded options, puts and calls, forward sale contracts and other swap, hedging and derivative transactions relating to our securities. The Board also has adopted a policy prohibiting our executive officers and directors from holding our securities in margin accounts or pledging our securities as collateral for a loan.

Board Leadership Structure

The positions of Chief Executive Officer and Chairman of the Board are held by separate individuals. Lester Knight has served as the Non-Executive Chair of the Board since 2008. The position of Non-Executive Chair is independent from management. As Non-Executive Chair, Mr. Knight sets the agendas for, and presides over, the Board meetings and also chairs executive sessions of the non-management directors. The Chief Executive Officer is also a member of the Board and participates in its meetings. The Board believes the separation of the positions of Chief Executive Officer and Chair is the appropriate structure at this time as it allows the Chief Executive Officer to focus on the management of the Company and the Chair to ensure that the Board is focused on its oversight responsibilities, including independent oversight of management.

Board Role in Risk Oversight

Risk is inherent and evolving in every business, and how well a business manages risk can ultimately determine its success. Our risk management program covers the range of material risks to Aon, including strategic, operational, financial, compliance, human capital, social and reputational risks. The Board oversees Aon’s risk management program and allocates

16 2021 Aon Proxy Statement

certain oversight responsibilities to its committees and sub-committees, as appropriate. Each committee regularly reports to the Board on risk matters under its purview. The Board and its committees periodically review our risk management policies, processes and controls (including enterprise risk management, or “ERM”).

Management carries out the daily processes, controls and practices of our risk management program, many of which are embedded in our operations. In addition, as part of our ERM process, management identifies, assesses, prioritizes and develops mitigation plans for Aon’s top material risks. The Board believes that establishing the right tone at the top and maintaining full and open communication between management and the Board are essential for effective risk management and oversight. As such, the Board and the committees regularly review and discuss significant risks with management, including strategy discussions and regular reviews of annual operating plans, financial performance, merger and acquisition opportunities and post-acquisition performance, human capital management and innovation, as well as presentations on specific risk areas. In addition, members of senior management attend Board and committee meetings (including private sessions with independent directors) and are available to address any questions or concerns raised by the Board related to risk management and any other matters. For more information about the Board’s engagement during 2020 throughout the COVID-19 pandemic, please see page 4 of this proxy statement.

Our Board and management recognize that the full spectrum of ESG risks are evolving in their significance to the business, and accordingly, oversight of ESG risks is a continuing and evolving commitment. As a professional services firm, Aon’s management and oversight of social and human capital risk is a priority. The Board (or through its committees) regularly reviews and discusses people-related risks, including colleague satisfaction and engagement survey results, pay equity, colleague well-being, succession planning and employment law matters, including COVID-19 response and ethics hotline complaints. In 2020, the Board formed the Inclusion & Diversity Sub-Committee to enhance the Board’s oversight of the company’s inclusion and diversity strategies and initiatives, including review and monitoring of the company’s policies and practices with respect to inclusion, diversity and equal employment opportunity.

Director Independence

Aon’s Governance Guidelines require that a majority of directors meet the categorical independence standards adopted by the Board, which will meet or exceed the independence requirements of the New York Stock Exchange (“NYSE”). The Governance Guidelines further provide that each of the Audit Committee, Governance/Nominating Committee and Compensation Committee be composed entirely of independent directors.

The Board has affirmatively determined that each nominee for director other than Mr. Case is independent under the categorical standards adopted by the Board, applicable legal requirements and the rules of the NYSE. Mr. Case is considered a management director because of his position as our Chief Executive Officer.

In determining that each of the non-management directors is independent, the Board also considered the following relationships that it deemed were immaterial to such director’s independence:

•

With respect to Mr. Knight, Mr. Campbell, Ms. Santona and Mr. Spruell, the Board considered that, in the ordinary course of business, Aon has sold services to, or received services from, a company or other entity at which the director is an employee and the amount that we received from or paid to the entity in any of the previous three fiscal years was below the greater of $1 million or two percent (2%) of that entity’s annual revenue; and

•

With respect to Mr. Knight, Mr. Campbell, Ms. Francis, Mr. Notebaert, Ms. Santona and Mr. Spruell, the Board considered that Aon or certain of its affiliates made charitable contributions in 2020 to organizations in which the director or the director’s spouse was an officer, director, or trustee. In each case, the amount that we contributed was below the greater of $1 million or two percent (2%) of that organization’s consolidated gross revenue.

Board of Directors and Committees

The Board met nine times in 2020, including three joint meetings with the Finance Committee and one joint meeting with the Organization and Compensation Committee and acted by unanimous written consent on two occasions during 2020. With the exception of Mr. Spruell, who joined the Board in October 2020, all nominees for director who served as a director in 2020 attended at least 75% of the total meetings of the Board and the committees on which they served. Since his appointment, Mr. Spruell has attended at least 75% of the meetings of the Board and the committees on which he serves.

2021 Aon Proxy Statement 17

In accordance with NYSE rules and the Governance Guidelines, non-management directors meet regularly in executive session without management. Mr. Knight chairs these executive sessions.

The Board has five standing committees: the Executive Committee, the Audit Committee, the Finance Committee, the Governance/Nominating Committee and the Organization and Compensation Committee. The Board has also established the Compliance Sub-Committee as a standing sub-committee of the Audit Committee and the Inclusion & Diversity Sub-Committee as a standing sub-committee of the Governance/Nominating Committee.

Executive Committee

When the Board is not in session, the Executive Committee is empowered to exercise the power and authority in the management of the business and affairs of Aon as would be exercised by the Board, subject to certain exceptions. The Executive Committee acted by unanimous written consent on four occasions in 2020.

Audit Committee

The primary purposes of the Audit Committee are to assist the Board with the oversight of: (i) the integrity of Aon’s financial statements and financial reporting process; (ii) Aon’s compliance with legal and regulatory requirements and ethics programs established by management and the Board; (iii) the engagement of Aon’s independent auditor and its qualifications, independence and performance; (iv) subject to the provisions of Irish law, the appointment and performance of Aon’s statutory auditor as required under Irish law; and (v) the performance of Aon’s internal audit function. The Audit Committee is authorized to retain outside counsel or other experts as it deems appropriate to carry out its duties and responsibilities.

The Board has also delegated to the Audit Committee the primary responsibility for the oversight of the Company’s risk management. The Audit Committee reviews and discusses with management Aon’s guidelines and policies with respect to risk assessment and enterprise risk management, including the major financial risk exposures facing the Company and the steps management has taken to monitor and control such exposures. The Audit Committee also has primary responsibility for oversight of cybersecurity risk and engages in regular discussion with management regarding cybersecurity risk mitigation and incident management. The Audit Committee also has general oversight responsibility for the Company’s legal, regulatory and ethics policies and programs and annually reviews the adequacy of those policies and programs, including Aon’s Code of Business Conduct. In addition, the Audit Committee periodically reviews with management any material correspondence with, or other action by, regulators or governmental agencies.

In 2020, the Audit Committee met nine times. The Board has determined that each of the members of the Audit

Committee is independent as defined by the rules of the NYSE and under the Company’s categorical independence standards, as well as Rule 10A-3 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”). In addition, as required by the rules of the NYSE, the Board has determined that all of the Audit Committee members are financially literate, and that Mr. Losh, Mr. Campbell and Mr. Conti are “audit committee financial experts” within the meaning of rules promulgated by the SEC.

Additional information regarding the Audit Committee’s responsibilities may be found in this proxy statement in the section captioned “Report of the Audit Committee.”

Compliance Sub-Committee

In light of the breadth and number of responsibilities that the Audit Committee must oversee and the importance of the evaluation and management of risk related to Aon’s compliance programs and policies, the Board formed the Compliance Sub-Committee, a standing sub-committee of the Audit Committee. The primary responsibilities of the Compliance Sub-Committee are to: (i) oversee matters of non-financial compliance, including Aon’s implementation of compliance programs, policies and procedures that are designed to be responsive to the compliance and regulatory risks facing Aon; (ii) assist the Audit Committee in fulfilling its oversight responsibilities for Aon’s compliance and ethics programs, policies and procedures; and (iii) perform any other duties as directed by the Audit Committee or the Board. The Compliance Sub-Committee reports regularly to the Audit Committee and the Board regarding its activities.

Each member of the Compliance Sub-Committee is independent as defined in the independence standards of the NYSE. The Compliance Sub-Committee met four times during 2020.

Finance Committee

The Finance Committee is responsible for assisting the Board with monitoring and overseeing Aon’s balance sheet, including Aon’s capital management strategy, capital structure, investments, returns and related policies. The Finance Committee also reviews certain proposed mergers, acquisitions, divestitures and strategic and

18 2021 Aon Proxy Statement

passive investments in accordance with policies established by the Board. In addition, the Finance Committee oversees the financial, investment and actuarial policies and objectives of Aon’s U.S. tax-qualified defined benefit plans, reviews the investment performance of non-U.S. benefit and retirement plans and reviews Aon’s major insurance programs.

Each member of the Finance Committee is independent as defined in the independence standards of the NYSE. The Finance Committee met seven times during 2020, including three joint meetings with the Board of Directors.

Governance/Nominating Committee

The Governance/Nominating Committee oversees the risks associated with Aon’s overall governance and: (i) identifies and recommends to the Board candidates for service on the Board; (ii) reviews and recommends the re-nomination of incumbent directors for each annual general meeting; (iii) reviews and recommends Board committee appointments; and (iv) leads the annual performance evaluation of the Board and its committees. In addition, the Governance/Nominating Committee develops and recommends the Governance Guidelines to the Board, reviews related party transactions and annually reviews compliance with share ownership guidelines.

Each member of the Governance/Nominating Committee is independent as defined in the independence standards of the NYSE. The Governance/Nominating Committee met five times and acted by unanimous consent one time during 2020.

Inclusion & Diversity Sub-Committee

In light of the importance of the evaluation, oversight and management of the Aon’s inclusion and diversity strategies and initiatives, the Board formed the Inclusion & Diversity Sub-Committee, a standing sub-committee of the Governance/Nominating Committee. The primary responsibilities of the Inclusion & Diversity Sub-Committee are to: (i) oversee management’s inclusion and diversity strategy and initiatives, including the efforts of the Company’s Global Inclusive Leadership Council; (ii) periodically review and monitor the Company’s policies and practices with respect to inclusion, diversity and equal employment opportunity; and (iii) perform any other duties as directed by the Governance/Nominating Committee or the Board.

The Inclusion & Diversity Sub-Committee membership was appointed in October 2020 and held its first meeting in February 2021.

Organization and Compensation Committee

The Organization and Compensation Committee (the “Compensation Committee”) assists the Board in carrying out its overall responsibilities with regard to executive compensation, including oversight of the determination and administration of our compensation philosophy, policies, programs and plans for executive officers and non-management directors. The Compensation Committee annually reviews and determines the compensation of Aon’s executive officers, including the Chief Executive Officer, subject, in the case of the Chief Executive Officer, to the input of the independent members of the Board. The Compensation Committee consults with the Chief Executive Officer on, and directly approves, the compensation of other executive officers, including special hiring and severance arrangements.

The Compensation Committee administers the Amended and Restated Aon plc 2011 Incentive Plan (and its predecessor plans) (the “Shareholder-Approved Plan”), including granting equity (other than awards to the Chief Executive Officer, which awards are approved by the independent members of the Board) and interpreting the Shareholder-Approved Plan and has certain settlor responsibilities with respect to our other U.S. employee benefit programs. In addition, the Compensation Committee reviews and makes recommendations to the Board concerning non-management director compensation and amendments to U.S. employee benefit plans and equity plans. The Compensation Committee reviews and discusses the compensation disclosures contained in the proxy statement. As part of these duties, the Compensation Committee reviews the risks associated with Aon’s compensation practices, including an annual review of Aon’s risk assessment of its compensation policies and practices for its employees. The Compensation Committee also reviews and monitors the Company’s policies and practices with respect to diversity, inclusion and equal employment opportunity.

Each member of the Compensation Committee is independent as defined in the independence standards of the NYSE. The Compensation Committee met seven times, including one joint meeting with the Board, and acted by unanimous consent three times during 2020. Additional information regarding the Compensation Committee’s responsibilities may be found in this proxy statement in the sections captioned “Compensation Committee Report” and “Compensation Discussion and Analysis.”

2021 Aon Proxy Statement 19

Other Corporate Governance Practices

Board and Committee Evaluations

Our Board of Directors engages in ongoing self-evaluation and assessment. Annually, the directors review and complete evaluations on Board effectiveness, committee performance and peer assessment. The Board retains an outside party to review the completed evaluations. Each of the Committees and the full Board discuss their self-assessments in executive sessions at least annually. The Governance/Nominating Committee periodically reviews the form and process for Board and Committee self-evaluations.

CEO Succession Planning

Our Independent Board Chair oversees the CEO succession planning process. The Board, at least annually, discusses CEO succession planning, including emergency succession plans and process. The Board also regularly reviews and discusses senior leadership succession planning and development.

Director Selection and Shareholder Recommendations

Consistent with the Governance Guidelines, the Governance/Nominating Committee seeks members from diverse backgrounds who combine a broad spectrum of experience and expertise with a reputation for integrity. The Governance/Nominating Committee also considers whether a potential nominee would satisfy independence standards adopted by the Board and the requirements of the NYSE.

The Board values diversity as a factor in selecting nominees to serve on the Board. In selecting nominees for director, the Governance/Nominating Committee considers professional background, reputation for integrity, leadership capabilities, skills and experience in the context of the needs of the Board, diversity, including gender and racial/ethnic diversity, and international experience and perspectives. Of the 12 director nominees for election at the Annual Meeting, 2 directors are Asian, 1 director is Black and 1 director is Latinx; 3 of the 12 director nominees are women. Although there is no specific policy with regard to the consideration of diversity in identifying director nominees, the Governance/Nominating Committee considers, and requests that the search firms it engages include, women and racially/ethnically diverse persons in potential director candidates for consideration by the Committee.

When a vacancy exists on the Board due to the expansion of the size of the Board or the resignation or retirement of an existing director, the Governance/Nominating Committee identifies and evaluates potential director nominees. The Governance/Nominating Committee has sole authority to retain and terminate any search firm to be used to identify director candidates and sole authority to approve such search firm’s fees and other retention terms. The Governance/Nominating Committee recommends potential director candidates to the full Board, which is responsible for final approval of any director candidate. This process is the same for director candidates who are recommended by our shareholders. The effectiveness of the nomination process, including the criteria used for selecting nominees for director, is evaluated by the Board each year as part of its annual self-evaluation process and by the Governance/Nominating Committee as it evaluates and identifies director candidates. Our newest director Mr. Spruell was appointed to the Board in October 2020 and will stand for election by the shareholders at the Annual Meeting. Mr. Spruell was suggested for consideration by the Governance/Nominating Committee by a non-management director.

The Governance/Nominating Committee will consider shareholder recommendations for director candidates. Recommendations, together with the name and address of the shareholder making the recommendation, relevant biographical information regarding the proposed candidate and a description of any arrangement or understanding between the shareholder and the proposed nominee, should be sent to the Company Secretary. Recommendations for director candidates to stand for election at the 2022 annual general meeting must be submitted in writing to the Secretary, Aon plc, Metropolitan Building, James Joyce Street, Dublin 1, Ireland. Recommendations will be forwarded to the Chair of the Governance/Nominating Committee for review and consideration. For further information, see “Shareholder Proposals for 2022 Annual General Meeting” on page 71 of this proxy statement.

Communications with the Board of Directors

Shareholders and other interested parties may communicate with the Board by contacting the non-management directors of Aon plc, c/o the Secretary, Metropolitan Building, James Joyce Street, Dublin 1, Ireland. Alternatively, shareholders and other interested parties may communicate with Aon’s non-management directors via electronic mail to the following address: corporate.governance@aon.com.

20 2021 Aon Proxy Statement

The non-management directors have established procedures for handling communications from shareholders and other interested parties. Communications are distributed to the Chair of the Governance/Nominating Committee, the full Board, the non-management directors, or to any individual director or directors as appropriate, depending on the facts and circumstances outlined in the communication. Solicitations, spam, junk mail and mass mailings, resumes and other forms of job inquiries, business solicitations or advertisements and frivolous or inappropriate communications will not be forwarded, but will be made available to any non-management director upon request.

Shareholder Engagement

In 2020, we continued our focus on regularly engaging with our shareholders. During these meetings, we discussed many topics, including the pending Willis Towers Watson transaction, which received 99% shareholder approval in August 2020, our corporate governance structure, our results and strategy and our corporate responsibility. We continued our conversations with our investors about our Board’s oversight of risks, in particular risks stemming from the COVID-19 pandemic and its impact on our business and the broader economy. Investors were generally supportive of many of the Company’s practices and highlighted the importance of engaging with them in the future on long-term corporate strategy and corporate social responsibility initiatives. These discussions provide valuable insights into our shareholders’ views. We plan to continue to actively engage with our shareholders to better understand and consider their views.

Majority Voting

The Articles require that directors be elected by majority vote in uncontested elections. In a contested election, directors will be elected by plurality vote. In addition, the Governance Guidelines provide that any incumbent director who fails to receive an affirmative majority of the votes cast, in person or by proxy, by shareholders entitled to vote at the Annual Meeting in an uncontested election (and who is not otherwise removed by ordinary resolution of the shareholders) must immediately offer to tender his or her resignation to the Board. The Board will then determine, through a process overseen by the Governance/Nominating Committee, whether to accept the resignation, reject the resignation, or take other action. The Board will act on the recommendation of the Governance/Nominating Committee.

Share Ownership Guidelines

The Board has adopted Share Ownership Guidelines for Non-Management Directors and Share Ownership Guidelines for Aon’s senior executives. The Share Ownership Guidelines for Non-Management Directors require each non-management director to hold an investment position in Class A Ordinary Shares equal to five times the annual director retainer and to provide a transition period of five years for non-management directors to achieve the requisite ownership level; provided, however, that each new non-management director is expected to hold 1,000 Class A Ordinary Shares within the first year of joining the Board. The guidelines serve to increase our non-management directors’ equity stakes in Aon and align Aon’s non-management directors’ interests more closely with those of Aon’s shareholders. Further information on the Share Ownership Guidelines for Aon’s senior executives can be found in the section captioned “Compensation Discussion and Analysis.”

Hedging and Pledging Shares

The Board has adopted a policy prohibiting all directors and employees from engaging in short sales, publicly traded options, puts and calls, forward sale contracts and other swap, hedging and derivative transactions relating to our securities. The Board also has adopted a policy prohibiting our executive officers and directors from holding our securities in margin accounts or pledging our securities as collateral for a loan.

Incentive Repayment Policy and Forfeiture Provisions

The Board has adopted an Incentive Repayment Policy applicable to Aon’s executive officers. Pursuant to the Incentive Repayment Policy, the Board may cancel or require reimbursement of any incentive payments or equity-based awards received if the incentive payment or equity award was based on the achievement of financial results that are subsequently restated. If the Board determines that the executive officer engaged in fraud that caused or partially caused the need for the financial restatement, the incentive payment or equity-based award is required to be forfeited or reimbursed in full. If the restatement was not the result of fraud by the executive officer, the Board may, to the extent allowed under applicable law, require forfeiture or reimbursement of the amount the incentive payment or equity-based award exceeded the lower amount that would have been made based on the restated financial results. In addition, beginning with equity-based awards granted in 2019, unvested equity-based awards are subject to forfeiture in the event of a material violation of the Company’s policies or procedures or a breach of applicable restrictive covenants.

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Attendance at Annual General Meeting

The Governance Guidelines provide that directors are expected to attend the annual general meeting. All of our then-serving Board members attended our 2020 annual general meeting virtually or in person.

Certain Relationships and Related Transactions

Aon has adopted a Related-Person Transaction Policy governing the review and approval of related party transactions. The terms of these procedures provide that the Governance/Nominating Committee will review transactions in which: (i) Aon is a party, participant, or has a direct or indirect material interest; (ii) the amount involved exceeds or reasonably can be expected to exceed $120,000; and (iii) any director, executive officer or holder of five percent (5%) or more of Aon’s voting securities, or an immediate family member of any such person, has a direct or indirect material interest. To facilitate the review and approval of related party transactions, Aon’s directors and executive officers complete an annual director and officer questionnaire and disclose all potential related person transactions involving themselves and their immediate family members. Throughout the year, directors and executive officers are required to notify Aon’s General Counsel of any potential related person transactions of which they become aware. Aon’s General Counsel reports these transactions, as well as any other related party transactions of which he is aware, to the Governance/Nominating Committee. The Governance/Nominating Committee considers all relevant facts of any related party transactions to determine whether to approve or ratify the transaction.

Compensation Committee Interlocks and Insider Participation

During 2020, the Compensation Committee was composed of Mr. Notebaert (Chair), Mr. Cai, Mr. Campbell, Ms. Francis, General Myers and Dr. Woo. No member of the Compensation Committee was, during 2020 or previously, an officer or employee of Aon or any of its subsidiaries. In addition, during 2020, there were no Compensation Committee interlocks required to be disclosed.

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Security Ownership of Directors and

Executive Officers

The following table sets forth the number of Class A Ordinary Shares beneficially owned as of April 8, 2021 by each of the nominees for director, by each of Aon’s NEOs and by Aon’s directors, nominees and executive officers as a group. As used in this proxy statement, beneficially owned means a person has, or may have within 60 days, the sole or shared power to vote or direct the voting of a security and/or the sole or shared investment power with respect to a security (i.e., the power to dispose or direct the disposition of a security). No shares held by Aon’s directors or executive officers are pledged as security. The address of each person named in the table below is c/o Aon plc, Metropolitan Building, James Joyce Street, Dublin 1, Ireland.



Name	Aggregate Number of Class A Ordinary Shares Beneficially Owned¹		Percent of Class²
Directors
Lester B. Knight³		244,629		*
Gregory C. Case⁴		1,286,723		*
Jin-Yong Cai		5,163		*
Jeffrey C. Campbell		8,944		*
Fulvio Conti		28,765		*
Cheryl A. Francis		25,617		*
J. Michael Losh⁵		35,512		*
Richard B. Myers		26,821		*
Richard C. Notebaert		45,721		*
Gloria Santona		36,521		*
Byron O. Spruell		575		*
Carolyn Y. Woo		26,630		*
Other NEOs
Christa Davies		199,571		*
Eric Andersen		113,492		*
Anthony Goland		29,341		*
John Bruno		75,789		*
All directors and executive officers as a group (20 persons)⁶		2,230,383		*

(1)	The directors, NEOs and all directors and executive officers of Aon combined, have sole voting power and sole investment power over the Class A Ordinary Shares listed, except as indicated in notes (3), (4), (5) and (6).

(2)	As of April 8, 2021, we had 226,153,397 Class A Ordinary Shares outstanding.

(3)	Includes 100,000 Class A Ordinary Shares that are beneficially owned by family partnership, 124,604 Class A Ordinary Shares owned by Mr. Knight’s spouse and 20,025 Class A Ordinary Shares owned in trusts.

(4)	Includes 400,000 Class A Ordinary Shares that are beneficially owned in trust and 393,604 Class A Ordinary Shares held by trusts for which an immediate family member serves as trustee.

(5)	Includes 20,604 Class A Ordinary Shares that are beneficially owned in trust.

(6)	Includes Class A Ordinary Shares that may be acquired by vesting of RSUs within 60 days after April 8, 2021.

*	An asterisk indicates that the percentage of Class A Ordinary Shares beneficially owned does not exceed 1% of our outstanding Class A Ordinary Shares.

2021 Aon Proxy Statement 23

Principal Holders of Voting Securities

As of April 8, 2021, the beneficial owners of 5% or more of Aon’s Class A Ordinary Shares entitled to vote at the Annual Meeting and known to the Company were:



Name and Address of Beneficial Owner	Number of Class A Ordinary Shares			Percent of Class⁽¹⁾

Massachusetts Financial Services Corporation 111 Huntington Avenue Boston, MA 02199		20,197,468	²		8.93	%

The Vanguard Group 100 Vanguard Blvd. Malvern, PA 19355		17,595,225	³		7.78	%

BlackRock, Inc. 55 East 52nd Street New York, NY 10055		17,307,328	⁴		7.65	%

(1)	As of April 8, 2021, we had 226,153,397 Class A Ordinary Shares outstanding.

(2)

Based upon information contained in a Schedule 13G/A filed with the SEC on February 11, 2021, pursuant to Rule 13d-1(b) of the Exchange Act. Massachusetts Financial Services Corporation is a parent holding company and has: (a) sole voting power as to 18,961,005 Class A Ordinary Shares; (b) shared voting power as to no Class A Ordinary Shares; (c) sole dispositive power as to 20,197,468 Class A Ordinary Shares; and (d) shared dispositive power as to no Class A Ordinary Shares.

(3)

Based upon information contained in a Schedule 13G/A filed with the SEC on February 10, 2021, pursuant to Rule 13d-1(b) of the Exchange. The Vanguard Group is a registered investment advisor and has (a) sole voting power as to no Class A Ordinary Shares; (b) shared voting power as to 405,401 Class A Ordinary Shares; (c) sole dispositive power as to 16,565,759 Class A Ordinary Shares; and (d) shared dispositive power as to 1,029,466 Class A Ordinary Shares.

(4)

Based upon information contained in a Schedule 13G/A filed with the SEC on February 2, 2021, pursuant to Rule 13d-1(b) of the Exchange Act. BlackRock, Inc. is a parent holding company and has: (a) sole voting power as to 14,948,976 Class A Ordinary Shares; (b) shared voting power as to no Class A Ordinary Shares; (c) sole dispositive power as to 17,307,328 Class A Ordinary Shares; and (d) shared dispositive power as to no Class A Ordinary Shares.

24 2021 Aon Proxy Statement

Proposal 2–Advisory Resolution on Executive

Compensation

The Board of Directors unanimously recommends that shareholders vote “FOR” advisory approval of the compensation of Aon’s NEOs.

What am I voting on?

In accordance with applicable law and Section 14A of the Exchange Act, we are providing shareholders with the opportunity to vote on an advisory resolution, commonly known as “say on pay,” approving Aon’s executive compensation as reported in this proxy statement. At our 2020 annual general meeting, we provided shareholders with the opportunity to vote on an advisory resolution regarding the executive compensation of our NEOs as disclosed in the proxy statement for the 2021 annual general meeting, and shareholders approved the proposal by a large majority. We currently conduct advisory “say-on-pay” votes on an annual basis, and we expect to conduct our next advisory vote at our 2022 annual meeting of stockholders.

We encourage shareholders to read the Compensation Discussion and Analysis beginning on page 27 of this proxy statement, which describes in detail how our compensation policies and procedures operate and are designed to achieve our compensation objectives of (1) directly linking the compensation of our NEOs to our performance, and (2) aligning the financial interests of our NEOs with those of our shareholders. We further encourage our shareholders to refer to the Summary Compensation Table for Fiscal Years 2020, 2019 and 2018, and other related tabular and narrative disclosures beginning on page 41 of this proxy statement, which provide detailed information on the compensation of our NEOs.

The Board and the Compensation Committee believe that the policies and procedures articulated in the Compensation Discussion and Analysis are effective in achieving our compensation objectives and that the design of our compensation program and the compensation awarded to our NEOs fulfill these objectives.

The form of shareholder resolution for this proposal is below.

RESOLVED THAT, the shareholders approve, on an advisory basis, the compensation of the Company’s named executive officers as described in the proxy statement for the 2021 Annual General Meeting of the Company under “Compensation Discussion and Analysis” and “Executive Compensation,” including the tabular and narrative disclosure contained in the proxy statement.

Is this vote binding on the Board?

As this vote is advisory, it will not be binding upon the Board or the Compensation Committee, and neither the Board nor the Compensation Committee will be required to take any action (or refrain from taking any action) as a result of the outcome of the vote on this proposal. The Compensation Committee will review and consider the outcome of the vote in connection with the ongoing review of Aon’s executive compensation programs.

2021 Aon Proxy Statement 25

Compensation Committee Report

The Organization and Compensation Committee of the Board of Aon has reviewed and discussed with management the Compensation Discussion and Analysis required by Item 402(b) of Regulation S-K and set forth in this proxy statement.

Based on its review and discussions with management, the Organization and Compensation Committee recommended to the Board that the Compensation Discussion and Analysis be included in this proxy statement and incorporated into Aon’s Annual Report on Form 10-K.

This Report is provided by the Organization and Compensation Committee, which is composed entirely of the following independent directors:


Richard C. Notebaert, Chair		Cheryl A. Francis
Jin-Yong Cai		Richard B. Myers
Jeffrey C. Campbell		Carolyn Y. Woo

26 2021 Aon Proxy Statement

Compensation Discussion and Analysis

This Compensation Discussion and Analysis (“CD&A”) describes our executive compensation program for our NEOs for 2020, who are listed below. We recommend that you read this section in conjunction with the executive compensation tables and corresponding footnotes that follow, as it provides context for the amounts shown in the tables and the footnote disclosures.



Name		Role
Gregory C. Case		Chief Executive Officer
Christa Davies		Executive Vice President and Chief Financial Officer
Eric Andersen		President
John Bruno (1)		Chief Operating Officer
Anthony Goland		Chief Innovation Officer

(1)	On January 25, 2021, Mr. Bruno notified the Company of his decision to step down from his position as Chief Operating Officer, effective immediately. Mr. Bruno will remain at the Company for a transition period to be determined.

Executive Summary

Who We Are

Aon is a leading global professional services firm providing a broad range of risk, retirement, and health solutions. Our approximately 50,000 colleagues in 120 countries empower results for clients by using proprietary data and analytics to deliver insights intended to reduce volatility and improve performance.

2020 Business Highlights

In assessing our performance, we focus on four non-GAAP metrics that we communicate to shareholders: organic revenue growth, expansion of adjusted operating margins, increase in adjusted diluted earnings per share, and increased free cash flow. These non-GAAP metrics should be viewed in addition to, not instead of, our consolidated financial statements and notes thereto. A reconciliation of these non-GAAP metrics to the most directly comparable GAAP metrics is set forth in Appendix A to this proxy statement.

In 2020, we continued to deliver against these four metrics:

•

Total revenue growth was flat and organic revenue growth was 1% in challenging macroeconomic conditions, reflecting strength in the core portions of our business, partially offset by a decline in the more discretionary portions.

•

Operating margin was 25.1% and adjusted operating margin was 28.5%, which reflects record adjusted operating margin driven by 1% organic revenue growth and expense discipline, including lower travel and entertainment expense, partially offset by a $47 million decrease in fiduciary investment income and ongoing investment in long-term growth.

•

Earnings per share was $8.45 and adjusted diluted earnings per share was $9.81, reflecting operational strength and effective capital management, highlighted by $1.8 billion of share repurchase during 2020, partially offset by an unfavorable impact from foreign currency translation.

•

Cash flow from operations was $2,783 million and free cash flow was $2,642 million, an increase of $1,032 million, or 64%, driven by working capital improvements, including improved collections and actions taken to proactively manage liquidity, a $288 million decrease in restructuring cash outlays, and strong operational improvement. The prior year included approximately $130 million of net cash payments related to legacy litigation and $75 million of capital expenditures related to a prior restructuring program.

Performing at the level of these metrics allows us to continue to execute on our goals of strategically investing in long-term growth, improving return on invested capital, and effectively allocating capital.

During 2020, we returned approximately $2.2 billion in excess capital to our shareholders, including $1.8 billion in share repurchases and $412 million in dividends, which highlights our strong cash flow generation and effective allocation of capital. During Mr. Case’s leadership, which began in April 2005, our average annual total shareholder return has been 17%, compared to the return of the benchmark S&P 500 of 8% and 11% for our direct peer averages (Arthur J. Gallagher & Co., Brown & Brown, Inc., Marsh & McLennan Companies, Inc., and Willis Towers Watson Public Limited Company). We believe we are well positioned to create long-term value by improving our growth profile and operating performance and generating strong free cash flow.

2021 Aon Proxy Statement 27

We compensate our senior executives through incentive programs that measure both long-term and short-term performance. Our long-term incentive program (described in this CD&A under “Leadership Performance Program Under Our Shareholder-Approved Plan”) is based on adjusted cumulative earnings per share (a measure driven by operational performance and capital management) across overlapping three-year performance periods. Our short-term incentive program (described in this CD&A under “Annual Incentive Awards Under Our Shareholder-Approved Plan”) is based on adjusted operating income, a measure driven by operating margin and organic revenue growth.

We achieved strong results against these two metrics, which were the key performance measures under our 2020 annual and 2018-2020 long-term incentive compensation programs. Set forth below are the results against these metrics as well as the results against their GAAP comparative metrics:

•

$2,781M Operating Income; $3,150M Adjusted Operating Income, an increase of 4% year-over-year

•

$19.11 Cumulative EPS for 2018-2020; $27.14 Adjusted Cumulative EPS for 2018-2020; $22.36 LPP Adjusted Cumulative EPS for 2018-2020, as compared to target LPP Adjusted Cumulative EPS of $21.47

Because our short-range or long-range corporate planning may dictate a change to the metrics we use over time, we expect to continue reassessing the metrics annually.

Features of Our Executive Compensation Program

The following table provides an overview of our compensation program elements for our NEOs. The guiding philosophy underlying our executive compensation program is to provide a fair, flexible, and market-based total compensation package that is meaningfully tied to the Company’s short- and long-term performance and aligned with the interests of our shareholders.



	Element	Description	Objectives
Fixed	Base Salary	Fixed amount of compensation for services provided during the year.	Intended to provide our executives with a predictable level of income; determined in view of job responsibilities, experience, contractual commitments, individual performance, and market pay data.
Performance-Contingent	Annual Incentive Compensation	Performance-based annual incentive determined and paid based on achievement of specified annual corporate performance objectives and individual review of executives’ contributions to business and financial results, delivery of key strategic initiatives, and personal leadership. Annual incentives, if paid, are generally made under our shareholder-approved 2011 Incentive Plan (our “Shareholder-Approved Plan”) in a combination of 65% cash and 35% in restricted share units that vest over a three-year period.	Intended to serve as a vehicle for recognizing annual results and performance, while the portion payable in time-vested restricted share units promotes retention and provides value tied to long-term Company performance.
	Long-Term Incentive Compensation	Performance-based long-term incentive determined and paid under our Leadership Performance Program (“LPP”). LPP awards are issued under our Shareholder-Approved Plan in the form of performance share units that vest upon achievement of specific corporate performance objectives over a three-year performance period.	Intended to encourage and reward long-term performance by giving executives a stake in the Company’s long-term financial success and promote retention.

28 2021 Aon Proxy Statement



	Element	Description	Objectives
Benefit Plans	Retirement and Health and Welfare Benefits	Standard 401(k) plan and health and welfare benefits as provided to non-executive full-time employees. We also offer a nonqualified supplemental savings plan to eligible employees who exceed statutory U.S. Internal Revenue Service (“IRS”) limits for participation in our 401(k) plan, as well as a nonqualified plan through which eligible employees may defer receipt of their salary and/or annual incentive payments.	Intended to provide competitive benefits to attract and retain talented employees.
Severance	Severance and Change in Control Benefits	Severance benefits payable upon certain qualifying terminations of employment without cause or with specified good reason, including in connection with a change in control.	Intended to provide a temporary income stream following termination of employment without cause or with specified good reason and, in the case of change in control protection, to ensure continuity and objectivity of management during a change in control event.
Other	Certain Other Benefits	Housing, tax equalization, and various cost of living payments made to certain NEOs in connection with their relocation to London for the Company’s redomestication, and continued following the Company’s reorganization in Ireland; limited personal use of Company aircraft; certain NEOs also receive annual health screenings, a supplemental insurance program, reimbursement for club dues, legal services, relocation benefits, and car allowances.	Intended to recognize and make NEOs whole for expenses incurred in connection with the Company’s U.K. redomestication and subsequent reorganization in Ireland; also intended to attract and retain committed employees and allow them to focus on job duties.

Our Pay for Performance Orientation and Executive Compensation Philosophy

The core principle of our executive compensation program continues to be pay for performance, as we continue towards our goal of being the leading global professional services firm focused on risk, health, and retirement. That core principle dictates that performance-based pay elements (which constitute the bulk of our NEOs’ total direct compensation) will not be earned or paid unless our shareholders also benefit. For 2020, performance-based compensation comprised approximately 92% of the total direct compensation for Mr. Case and averaged approximately 84% of the total direct compensation for our other NEOs:

LOGO

2021 Aon Proxy Statement 29

The “performance-based” pay component of the above graphs is the sum of (1) the cash portion of the NEO’s bonus paid for 2020 performance, plus (2) the target value of all performance-based equity awards granted to the NEO for 2020 performance or during 2020. The “fixed” pay component is the NEO’s 2020 base salary. For our NEOs other than Mr. Case, the actual performance-based amount of total direct compensation ranged from 78% to 89%. Please refer to the Summary Compensation Table below for complete disclosure of the total compensation paid to our NEOs serving in that capacity during the prior three years.

In addition to our focus on pay-for-performance, our compensation program is complemented by several practices designed to align with the long-term interests of our shareholders:


Share Ownership Guidelines		Our share ownership guidelines are designed to increase executives’ equity stakes in Aon and to align executives’ interests more closely with those of our shareholders. The guidelines provide that our CEO should attain an investment position in Class A Ordinary Shares equal to six times his annual base salary and each other executive officer, including each of our other NEOs, and should attain an investment position in Class A Ordinary Shares equal to three times his or her annual base salary. The guidelines also establish equity retention rules generally requiring that net shares received through the exercise of share options, the vesting of restricted share units, and the vesting of performance share units are retained until the required investment position is achieved. Class A Ordinary Shares counted toward these guidelines include any shares owned outright, shares owned through an Aon-sponsored savings or retirement plan, shares purchased through an Aon-sponsored employee share purchase plan, shares obtained through the exercise of share options, and shares issued upon the vesting of restricted share units or performance share units. Each of our NEOs held the requisite number of shares under the guidelines as of December 31, 2020. Mr. Case has agreed to maintain an investment position in Class A Ordinary Shares in excess of those required under our share ownership guidelines. In his employment agreement, he agreed to maintain an investment position equal to 20 times his annual base salary.
Hedging and Pledging Policies		We have a policy prohibiting all employees, executive officers, and directors from engaging in short sales, publicly traded options, puts and calls, forward sale contracts, and other swap, hedging, and derivative transactions relating to our securities. We also maintain a policy prohibiting our executive officers and directors from holding our securities in margin accounts or pledging our securities as collateral for a loan.
Independent Compensation Consultant		The Compensation Committee retains an independent compensation consultant to provide advice and market data to bolster the Compensation Committee’s decision-making.
Clawback Policy and Forfeiture Provision		We have adopted an Incentive Repayment Policy applicable to our executive officers. Pursuant to the Incentive Repayment Policy, the Board may cancel or require reimbursement of any incentive or equity-based award received if such award was based on the achievement of financial results that are subsequently restated. If the Board determines that the executive officer engaged in fraud that caused or partially caused the need for the financial restatement, the incentive payment or equity-based award is required to be forfeited or reimbursed in full. If the restatement was not the result of fraud by the executive officer, the Board may, to the extent allowed under applicable law, require forfeiture or reimbursement of the amount by which the incentive payment or equity-based award exceeded the lower amount that would have been paid based on the restated financial results. In addition, beginning with equity-based awards granted in 2019, unvested equity-based awards are subject to forfeiture in the event of a material violation of the Company’s policies or procedures or a breach of applicable restrictive covenants.

30 2021 Aon Proxy Statement

2020 Executive Compensation Highlights

Annual Incentive Compensation. Annual incentive bonuses paid to our NEOs reflected our application of the incentive pool funding guidelines adopted by the Compensation Committee (which are based on a comparison of current year adjusted operating income results against the prior year), as well as the Compensation Committee’s evaluation of each NEO’s contributions to our business and financial results, delivery of key strategic initiatives, and personal leadership qualities. Target annual incentive opportunities for our NEOs for 2020, as a percentage of base salary, remained flat year over year. Once determined, annual incentives to our NEOs were paid 65% in the form of cash and 35% in the form of time-vested restricted share units in order to provide value to our executives that is tied to the long-term performance of the Company. Annual incentive bonuses for 2020 were paid to our NEOs in early 2021 following the Company’s achievement of adjusted operating income of $3,150 million. For purposes of determining the annual incentive award funding, the Compensation Committee adjusted this amount downward to $3,025 million to exclude $125 million of restructuring savings. The annual incentive awards are described in more detail in the section captioned “Annual Incentive Awards under Our Shareholder-Approved Plan” below.

The Executive Compensation Process

Process of Determining Executive Compensation

Management assists the Compensation Committee in developing and administering our executive and director compensation programs. Direct responsibilities of management include, but are not limited to:

•

Recommending executive compensation adjustments and short- and long-term incentive awards and other benefits, where applicable, for executive officers other than our CEO;

•

Providing ongoing review of the effectiveness of our executive compensation programs and alignment of the programs with our business and strategic objectives;

•

Designing and recommending appropriate amendments to our long-term and short-term cash and equity-based incentive plans for executives; and

•

Designing and recommending appropriate amendments to our employee benefit plans.

In the first quarter of 2020, our independent directors evaluated our CEO’s performance and compensation. At that time, the Compensation Committee also evaluated the performance and reviewed the compensation of our other executive officers. During this review, the Compensation Committee approved for each executive officer a target annual incentive for 2020 performance and the specific corporate performance metrics that our performance would be measured against for purposes of this incentive award. The Compensation Committee also approved in March 2020 a target number of performance share units to be awarded to each executive officer under the LPP.

In early 2021, in connection with the Compensation Committee’s annual compensation review, management presented the Compensation Committee with compensation tally sheets reporting compensation paid for the prior four years and the best-available competitive pay data. The Compensation Committee also reviewed and considered Aon’s overall performance against targets that were established for 2020. This review culminated in certain compensation decisions made by the Compensation Committee with respect to our executive officers during the first quarter of 2021, which are described in more detail below.

2021 Aon Proxy Statement 31

Relationship with Executive Compensation Consultant

The Compensation Committee retains Frederic W. Cook & Co., Inc. (“FW Cook”) as its independent compensation consultant. FW Cook provides expertise and advice on various matters coming before the Compensation Committee. FW Cook is engaged by, and reports directly to, the Compensation Committee, and does not advise management or receive other compensation from Aon. FW Cook typically participates in all Compensation Committee meetings where executive compensation matters are discussed and communicates with the Chair of the Compensation Committee between meetings. During 2020, FW Cook assisted the Compensation Committee by: advising on our compensation philosophy, objectives, and strategy; developing criteria for identification of our peer group for executive and Board compensation and Company performance review purposes; reviewing management’s design proposals for short-term cash and long-term equity incentive compensation programs; assessing risks arising from our compensation policies and practices; providing change in control severance calculations for our NEOs in the 2020 annual proxy disclosure; providing compensation data from our peer group proxy and other disclosures; advising on the terms and conditions of the renewal of employment agreements and transition to employment letters with our senior executive officers; advising and providing comments on management’s recommendations regarding executive officers’ annual incentives for 2020 and equity-based awards granted in 2020; reporting on executive-compensation related trends and regulatory initiatives; reporting on the impact of the COVID-19 pandemic on executive compensation and director pay programs at peer group companies; and advising on potential alternatives for Aon’s programs. Management periodically retains other consulting firms to provide pay survey data and other non-executive compensation services that may be presented to or reviewed by the Compensation Committee.

The Compensation Committee has assessed the independence of FW Cook pursuant to SEC and NYSE rules and concluded that no conflict of interest exists that would prevent FW Cook from serving as an independent consultant to the Compensation Committee.

How We Determine Total Compensation

The Compensation Committee generally targets a competitive level and mix of total direct compensation elements using market data as a reference point. For 2020, the Compensation Committee did not use a specific formula or comparative percentile targets to determine total compensation, individual components of compensation, or the relative mix of pay components, and the establishment of compensation levels in 2020 was not a mechanical process. Rather, the Compensation Committee used its judgment and business experience. The Compensation Committee’s overall intent was to evaluate the various elements of total compensation so that the emphasis of the Company’s compensation program was on its variable components of pay, including long-term equity awards and annual bonus awards, the value of which fluctuates based on Aon’s performance.

Use of Tally Sheets

The Compensation Committee regularly reviews compensation tally sheets. The tally sheets assign dollar amounts to each component of the executive’s compensation, including base salary, annual incentives (target and actual), long-term incentives granted and outstanding, employee benefits (including health care and qualified and nonqualified retirement plans), relocation benefits including income tax equalization, perquisites, and potential change in control severance payments. The tally sheets are presented to the Compensation Committee to help ensure that it is aware of all rewards components and the value of such components when making compensation decisions.

Involvement of Mr. Case in the Compensation Process

Each year, the Compensation Committee approves all elements of compensation for our NEOs and other executive officers (other than Mr. Case). These decisions are typically made during the annual compensation review process conducted in the first quarter of the year. The Compensation Committee solicits certain recommendations from Mr. Case and our Chief People Officer.

Mr. Case recommends to the Compensation Committee the equity award, annual incentive payment, and base salary adjustments, if any, for the executive officers who report directly to him. He has direct knowledge of the contributions made to Aon by these executive officers and he shares this knowledge with the Compensation Committee and provides feedback on the performance of his direct reports.

32 2021 Aon Proxy Statement

During the annual review process, our Chief People Officer and the Chair of the Compensation Committee work together on Mr. Case’s annual evaluation report, which summarizes Mr. Case’s qualitative and quantitative performance for the year. The report is considered, along with other factors (including the Compensation Committee’s own assessment of Mr. Case’s performance, relevant market data, and Aon’s overall performance), in recommending Mr. Case’s compensation to the independent directors of the Board.

The Compensation Committee has the ultimate authority to make compensation decisions for our NEOs and other executive officers except for Mr. Case, whose compensation is approved by the independent directors of the Board. The Compensation Committee discusses its preliminary compensation decisions with the independent members of the Board who do not serve on the Compensation Committee. This process garners additional input from those directors regarding the executives’ performance. The sharing of performance review information also aids the directors in carrying out their succession planning responsibilities. After considering input from those directors, the Compensation Committee makes its final determinations.

Mr. Case, together with our Chief People Officer and our Chief Financial Officer, makes recommendations to the Compensation Committee relating to the corporate performance targets to be established under Aon’s annual incentive and long-term equity incentive programs. The Compensation Committee reviews such recommendations with FW Cook and reserves the ultimate authority to set such targets and to determine whether such goals were achieved.

Result of Advisory Vote by Shareholders on Our “Say on Pay” Proposal

The Compensation Committee considered the results of the advisory vote by shareholders on the “say on pay” proposal presented to our shareholders at our 2020 annual general meeting of shareholders. As reported in our Current Report on Form 8-K, filed with the SEC on June 25, 2020, approximately 92% of shareholder votes cast at that meeting were voted in support of the compensation program offered to our NEOs. Accordingly, the Compensation Committee made no changes to our executive compensation programs.

Internal Pay Relationships

In determining an executive officer’s target annual incentive or long-term performance award value, the Compensation Committee will, from time to time, consider internal pay relationships. However, the Compensation Committee has not adopted a broad internal pay equity policy pursuant to which each executive officer’s compensation, or one or more components thereof, is related to or benchmarked against the compensation of other executive officers.

Analysis of Key 2020 Compensation Decisions

Peer Group

The Compensation Committee selects our executive compensation peer group based on a process that considers objective criteria including: industry segment; revenues, market capitalization, and employee headcount; business complexity; and global footprint. We also consider peers of our direct peers (“peers of peers”) and proxy-advisor peer groups. Our goal is to have relevant market data to inform our decisions on pay levels and practices. As such, we strive for a peer group that is balanced with larger and smaller companies in a comparable range, and to have continuity through an annual review process.

The defined criteria used to establish our peer group includes global financial services industry companies or major consulting firms with which we compete for executive talent and/or financial capital that are between one-fourth and four times our size in average market capitalization (calculated over the most recent eight quarters to reduce volatility), between one-fourth and four times our size in trailing four-quarter revenues, and latest year total assets less than $500 billion.

2021 Aon Proxy Statement 33

In 2019, we reviewed our peer group with FW Cook and concluded that based on our criteria, for 2020, The Allstate Corporation should be removed, while BlackRock and IHS Markit should be added. The Compensation Committee referred to the 2020 peer group when determining the actual annual incentive awards paid in 2021 related to 2020 performance. In 2020, we again reviewed our peer group with FW Cook and concluded that DXC Technology Solutions Corporation should be removed as it no longer meets our defined criteria, and that Automatic Data Processing should be added in its place, to form our 2021 peer group. Our 2020 and 2021 peer group members are listed below.


2021 Peer Group

Accenture plc	Fidelity National Information Services	Northern Trust Corporation

A.J. Gallagher & Co.	Fiserv, Inc.	S&P Global

Automatic Data Processing	IHS Markit	State Street

Bank of New York Mellon	Marsh & McLennan Companies, Inc.	Willis Towers Watson plc

BlackRock	Moody’s Corporation

Cognizant Technology Solutions Corp.	Morgan Stanley


2020 Peer Group

Accenture plc	Fidelity National Information Services	Northern Trust Corporation

A.J. Gallagher & Co.	Fiserv, Inc.	S&P Global

Bank of New York Mellon	IHS Markit	State Street

BlackRock	Marsh & McLennan Companies, Inc.	Willis Towers Watson plc

Cognizant Technology Solutions Corp.	Moody’s Corporation

DXC Technology	Morgan Stanley

Base Salary

Using the peer group and executive compensation review processes outlined above, the Compensation Committee annually considers and reviews salaries for our executive officers. While base salaries for our senior executives are adjusted infrequently, they may be occasionally adjusted to, among other things, recognize changes in job responsibilities or to bring the fixed component of an executive’s total compensation in line with his or her peers at the Company or the industry generally. Where approved, base salary adjustments generally take effect on April 1. The base salaries for our NEOs were not adjusted in 2020.

As part of the actions that we took to address COVID-19 and the resulting impact on our business, operations, and employees, each of our NEOs agreed to a temporary 50% reduction in his or her base salary from May 1, 2020 through November 1, 2020, at which point the foregone amounts were repaid.

Long-Term Leadership Performance Program under Our Shareholder-Approved Plan

The LPP is a sub-plan of our Shareholder-Approved Plan, which means that LPP awards are subject to terms approved by our shareholders. Each award granted under the LPP consists of performance share units that are eligible to vest over a three-year period based on achievement of cumulative adjusted EPS targets over that period. The Compensation Committee historically has approved LPP awards for our NEOs each year. The three-year LPP performance cycles run concurrently, so we may have up to three active cycles during a given year. For example, during 2020, our NEOs held LPP 13, LPP 14, and LPP 15 awards (for the 2018-2020, 2019-2021, and 2020-2022 performance periods, respectively). This design is intended to ensure that our NEOs remain focused on long-term sustainable performance.

During the first quarter of 2020, we granted performance share units to our executive officers, including each NEO, pursuant to LPP 15 (2020-2022 performance period). During the first quarter of 2021, we determined our actual levels of achievement under LPP 13 (2018-2020 performance period).

LPP 15 (2020 Grant for 2020-2022 Performance Period). This is our fifteenth annual three-year performance cycle for long-term incentive awards granted to our most senior leaders. The LPP is intended to further strengthen the relationship between

34 2021 Aon Proxy Statement

capital accumulation for our executives and long-term financial performance of the Company and increasing shareholder value. The performance share units awarded under LPP 15 are payable (to the extent earned) in the form of Class A Ordinary Shares. The grant date value of the awards (at target) was determined and approved by the Compensation Committee. From that value, the number of target performance share units was calculated on the date of grant based on that day’s closing price for Class A Ordinary Shares on the NYSE. The performance share units under LPP 15 will be earned and settled in a range of 0% (if the threshold level is not achieved) to 200% of the target number of shares based on the Company’s cumulative adjusted EPS over the three-year performance period.

The performance results for LPP 15 will be measured against three-year publicly reported adjusted cumulative EPS growth rate, subject to limited adjustments set forth in the program documentation at the beginning of the three-year period. The adjustments are intended to exclude the impact of unusual or infrequently occurring items, to provide a target that, while challenging, eliminates the impact of certain events and circumstances outside of the control of the relevant executive officers. The Compensation Committee’s selection under LPP 15 of the three-year performance period and cumulative adjusted EPS financial performance metric is intended to provide the award recipients a reasonable period within which to achieve and sustain what are intended to be challenging long-term growth objectives. The Compensation Committee believes adjusted EPS is a more effective measure of Company performance for purposes of motivating executive performance than against EPS calculated in accordance with U.S. GAAP, as the adjusted measure provides a target that is within the executives’ control and area of accountability. Further, the Company believes that adjusted EPS provides a perspective on the Company’s ongoing core operating performance that is consistent with how shareholders measure our success and that creates transparency and clarity for participants.

In determining the individual awards under LPP 15, the Compensation Committee considered internal pay relationships, the award recipient’s compensation mix, and total direct compensation, including the recipient’s total direct compensation for 2019 relative to similarly situated executives at our 2020 peer group members. The Compensation Committee also considered the continued efforts of our NEOs in connection with the Willis Towers Watson combination, particularly in light of an increasingly volatile global market. All of these considerations, taken together, account for the increased award amounts under LPP 15 for the 2020-2022 performance period relative to recent performance periods. For further information regarding individual awards under LPP 15, see footnote (1) in the Summary Compensation Table below, and also the Grants of Plan-Based Awards in Fiscal Year 2020 below.

LPP 13 (2018 Grant for 2018-2020 Performance Period). In early 2021, we determined the actual achievement under LPP 13. The performance period for LPP 13 ended on December 31, 2020.

LPP 13—Performance Share Units (Performance Period 1/1/2018—12/31/2020)



Metric	Threshold (50% Payout)			Target (100% Payout)		Maximum (200% Payout)
Cumulative Adjusted EPS		$	20.68		$21.47		$	24.71
					Actual		$	22.36

For LPP 13, the cumulative adjusted EPS goals from continuing operations ranged from a threshold level of $20.68, below which no payout would occur, to $24.71 or higher, which would yield shares equal to 200% of the target number. A result of $21.47 in cumulative adjusted EPS from continuing operations would have yielded shares equal to 100% of the target number. This target represented a 19.6% increase over the EPS target for the twelfth cycle of our LPP established for the performance period from 2017 through 2019 (“LPP 12”). Our actual cumulative adjusted EPS from continuing operations for the three-year period of 2018-2020 (after permitted adjustments, as described below) was $22.36, resulting in a payout at 154.9% of the target number of shares awarded.

The adjusted EPS from continuing operations results for LPP 13 include adjustments detailed by the plan governing LPP 13 and approved by the Compensation Committee. For each year of the performance period associated with LPP 13, adjustments to EPS from continuing operations were approved by the Compensation Committee to address the impact of restructuring savings. Each NEO received a distribution under LPP 13.

We do not pay dividends or dividend equivalents on performance share units.

2021 Aon Proxy Statement 35

LPP Adjustments for Restructuring. We consider underlying restructuring charges, as well as the resulting savings, to be unusual in nature and infrequently occurring and, therefore, consider these transactions for adjustments when assessing LPP performance. Consistent with LPP 12, for LPP 13 the Compensation Committee determined that, given the underlying nature of the restructuring savings and the fact that the benefits are realized in multiple subsequent years, it was appropriate to adjust out the majority of the cumulative savings, rather than the incremental savings, on a go-forward basis. No further adjustments for this restructuring program will be made to LPP 14 (2019-2021) or subsequent programs, as full knowledge of the impact of the restructuring savings was considered when establishing performance targets.

Annual Incentive Awards under Our Shareholder-Approved Plan

Annual Incentives. Under our Shareholder-Approved Plan, the Compensation Committee annually approves the framework for our annual incentive compensation plan, including the applicable Aon-wide performance metric and minimum achievement threshold against that performance metric. If the metric is not achieved, no annual bonuses are payable under our Shareholder-Approved Plan. If the minimum achievement threshold is met, our Shareholder-Approved Plan allows for the payment of current-year annual incentives to our executive officers up to a cap of the lesser of $10 million or the maximum annual incentive otherwise established by the Compensation Committee for each executive officer. For 2020, the Compensation Committee established a cap of 200% of each NEO’s target annual incentive.

In the first quarter of 2020, the Compensation Committee set 2020 annual incentive eligibility for our NEOs. For each NEO, annual incentive eligibility was set as a target percentage of the executive’s base salary at year end (and, for Ms. Davies, her annual foreign service allowance received in connection with her relocation to London). Target annual incentive opportunities for our NEOs for 2020, as a percentage of base salary, remained flat year over year. The target annual incentives for each of our NEOs are shown in the table below:


NEO	2020 Target Annual Incentive			2020 Target as% of Base Salary
Gregory C. Case		$	3,000,000		200	%
Christa Davies		$	1,680,000		150	%
Eric Andersen		$	1,000,000		100	%
John Bruno		$	950,000		100	%
Anthony Goland		$	900,000		100	%

Our Shareholder-Approved Plan does not provide guidelines or formulas for determining the actual annual incentives payable to our executive officers once the metric is achieved. If the metric is achieved, our Shareholder-Approved Plan allows the Compensation Committee to award an annual incentive up to the previously established cap. As explained below, for 2020, the Compensation Committee adopted a framework (the “Senior Executive Incentive Compensation Plan”) for determining actual annual incentives to be paid if the metric under our Shareholder-Approved Plan was achieved.

2020 Performance Metrics. In the first quarter of 2020, the Compensation Committee determined that 2020 Aon-wide performance would be measured by growth in adjusted operating income (“OI”) for 2020 (as adjusted for unusual or infrequently occurring items) as compared to a 2019 baseline adjusted OI number of $3,025 million. The Compensation Committee set the minimum achievement threshold at 70% of the 2019 adjusted OI, or $2,118 million. The Compensation Committee retained the discretion to further adjust OI under the plan for extraordinary, unusual, or infrequently occurring items. The Compensation Committee selected OI as the measure to emphasize performance of Aon as a whole and directly link executives’ awards to Aon’s key business initiatives of delivering distinctive client value and achieving operational excellence.

The Compensation Committee set the minimum threshold at 70% because it believed performance below that level would not create enough value for the Company’s shareholders and, therefore, should not result in annual incentive payments. If the minimum achievement threshold is satisfied, an annual incentive pool may be funded as described below under “Determining 2020 Annual Incentives.”

2020 Actual Performance. The Company’s adjusted OI for 2020 was $3,150 million. For purposes of determining 2020 annual incentives, however, the Compensation Committee adjusted that amount downward to $3,025 million to exclude $125 million of restructuring savings. The $3,025 million amount was 100% of the 2019 baseline, which exceeded the minimum threshold of 70% established under our Shareholder-Approved Plan.

36 2021 Aon Proxy Statement

Determining 2020 Annual Incentives. In the first quarter of 2020, the Compensation Committee approved the Senior Executive Incentive Compensation Plan for funding the total annual incentive pool under our Shareholder-Approved Plan for members of the Company’s senior management team (including our NEOs). That group included each of our NEOs. The rationale for establishing this funding framework was to provide executives with a clear connection between the expected reward and the required performance, as well as a basis for annual incentive payouts. Under those guidelines, the size of the incentive pool generally equals the aggregate target annual incentives for participants in the Company’s Senior Executive Incentive Compensation Plan, multiplied by the percentage increase in OI from the 2019 baseline to 2020 (reduced by 200 basis points), although the CEO retains the discretion to approve increases (up to 10%, subject to Compensation Committee consent) and decreases (up to 20%) in the size of the incentive pool. In other words, the incentive pool is only funded at target if there is a 2% increase in adjusted OI over the previous year. However, no individual could receive an award in excess of the maximum amount established by the Committee (the lesser of $10 million or two times his or her target annual incentive).

In accordance with our Shareholder-Approved Plan, the Senior Executive Incentive Compensation Plan would not be funded for 2020 unless Aon achieved the minimum threshold of 70% of the 2019 baseline. After determining that the minimum threshold had been achieved, the Compensation Committee met in February 2021 to determine the funding status of the incentive pool for 2020. After application of the formula guidelines described above, the total incentive pool reserved for members of the Company’s senior management team (including our NEOs), was determined to be approximately $9.1 million. Pursuant to the terms of the Senior Executive Incentive Compensation Plan, the CEO, in consultation and with the consent of the Compensation Committee, increased the amount of the aggregate pool by 10%, resulting in a total incentive pool of approximately $10.1 million. The increase was attributable to the overall Company performance combined with the team efforts of the senior executives (including our NEOs) to accomplish the important milestones of signing of the business combination agreement with Willis Towers Watson plc and preparing for the proposed combination. None of the NEOs received their maximum annual incentive of the lesser of $10 million or two times their target annual incentive. Each NEO received in the range of 0% to 150% of their target annual incentive, other than Mr. Case, who received an annual incentive of $3.45 million, or 115% of target annual incentive.

The following table sets forth the actual annual incentive paid to each of our NEOs under the Senior Executive Incentive Compensation Plan for the year:


NEO	2020 Actual Annual Incentive			2020 Actual Annual Incentive as % of Base Salary
Gregory C. Case		$	3,450,000		230	%
Christa Davies		$	2,000,000		200	%
Eric Andersen		$	1,500,000		150	%
John Bruno		$	0		0	%
Anthony Goland		$	585,000		65	%

In determining annual incentives for our NEOs, the Compensation Committee (or, with respect to Mr. Case, the independent members of the Board) considered account several factors, including Mr. Case’s compensation recommendations for the NEOs (other than himself), business and financial results, individual delivery of key strategic initiatives, personal leadership qualities, and annual incentives for similarly situated executives at our 2020 peer group members.

Regarding Mr. Case, the independent members of the Board determined that, under his leadership, the Company delivered impressive progress across the four key metrics that we communicate to shareholders: organic revenue growth, adjusted operating margins, adjusted diluted earnings per share, and free cash flow. Set against the public health and economic impact of COVID-19 and an unprecedented level of global volatility, organic revenue growth was 1%, operating margin on an adjusted basis increased 100 basis points to 28.5%, adjusted EPS increased 7% to $9.81 and free cash flow increased 64% to $2,642 million. During 2020, the company deployed $2.2 billion of capital through share repurchases and dividends. Under Mr. Case’s leadership, Aon also made key progress on strategic initiatives including the incorporation from the UK to Ireland, a definitive agreement to combine Aon plc and Willis Towers Watson, ten other key M&A transactions including CoverWallet, increased leverage of the Aon Business Services platform and investment in key opportunities under the New Ventures Group. Mr. Case demonstrated exemplary leadership navigating COVID, social unrest, and other issues resulting in record-

2021 Aon Proxy Statement 37

high colleague engagement measures, and he championed significant inclusion and diversity initiatives including the launch of the Global Inclusive Leadership Council and formation of a new subcommittee of the Board focused on inclusion and diversity.

Regarding Ms. Davies, the Compensation Committee determined that her individual efforts contributed substantially to the Company’s impressive business and financial results in 2020, including the four key metrics that we report to shareholders: organic revenue growth, adjusted operating margins, adjusted diluted earnings per share, and free cash flow. In the face of the extraordinary economic challenges of the global pandemic, Ms. Davies demonstrated exceptional management of the firm’s balance sheet, including term debt issuance and no draw against credit facilities, and delivered significant free cash flow improvements and a record 23.9% cash flow margin, driven in part by approximately $500 million of working capital improvement from proactive liquidity management. Her leadership was instrumental in delivering another 100 basis points of adjusted margin improvement and our strong adjusted earnings per share results. Ms. Davies also led the Company’s long-term capital investment strategy, including the definitive agreement to combine Aon plc and Willis Towers Watson plc and the acquisition of CoverWallet, led significant shareholder engagement efforts, and worked with other key leaders to achieve a distinctive return on invested capital of 23.5%. Ms. Davies has role modeled a focus on inclusion and diversity in colleague interactions and the development of key talent, inspiring multiple senior leaders to similarly take actions.

Regarding Mr. Andersen, the Compensation Committee determined that his individual efforts contributed substantially to the Company’s financial results in 2020 and positive progress against the four key metrics that we communicate to shareholders: organic revenue growth, adjusted operating margins, adjusted diluted earnings per share, and free cash flow. Despite the COVID-19 pandemic, Mr. Andersen was instrumental in delivering strong organic revenue growth of 10% in Reinsurance and 3% in Commercial Risk Solutions. As newly appointed President of Aon in 2020, he continues drive realization of the Aon United operating model. Under Mr. Andersen’s leadership, Aon fully scaled the Delivering Aon United strategy, increased client satisfaction, and delivered innovative solutions to clients, all while successfully transitioning the vast majority of colleagues to remote work. Additionally, Mr. Andersen has co-led integration planning for the pending combination of Aon plc and Willis Towers Watson plc. Mr. Andersen’s leadership has been instrumental in maintaining colleague engagement and retention through the events of 2020 and he has visibly sponsored the firm’s inclusion and diversity initiatives, enabling leaders to implement meaningful, data-driven strategies within their businesses.

Regarding Mr. Bruno, as noted above, he notified the Company on January 25, 2021 of his decision to step down from his position as Chief Operating Officer, effective immediately. As a result, the Compensation Committee determined to award him no annual bonus in respect of 2020 performance. Mr. Bruno will remain at the Company for a transition period to be determined. The Compensation Committee’s decision to award Mr. Bruno no annual bonus for 2020 may be taken into account in determining any future compensation.

Regarding Mr. Goland, the Compensation Committee determined that under his leadership, the firm continued to effectively identify, develop and scale the promising innovation priorities to support clients and expand Aon’s addressable market. Notable progress was made in accelerating and commercializing the firm’s unique, market-leading intellectual property (IP) solution with a first-of-its-kind IP lending transaction involving a leading technology company and a pension fund. Progress was also made in advancing our digital client solutions with the integration of the Cover Wallet business with Aon’s existing capabilities and solutions and with the development of an integrated roadmap for accelerated growth. Due to the impact of the pandemic, development of other growth opportunities was more limited, and overall achievement of revenue growth did not meet the high aspirational targets established for the New Ventures Group portfolio at the beginning of the year. Mr. Goland has been a strong advocate of inclusion and diversity within the firm and has led the development of sponsorship programs across the New Ventures Group.

2021 Annual Incentive Design Changes. We believe our people and culture power the Aon United growth strategy and enable us to deliver the best solutions to clients from across the firm. Given the importance in creating sustainable, long-term value, we will integrate people and culture imperatives into our incentive program. Specifically, in 2021, an inclusion and diversity (I&D) component will be incorporated into our annual Senior Executive Incentive Compensation Plan. This change is intended to further motivate our executive leadership team to achieve Aon’s I&D initiatives objectives while also delivering strong financial results. Previously, 100% of the Senior Executive Incentive Compensation Plan funding was based on year-over-year growth in adjusted operating income less a 200 basis point hurdle. Beginning in 2021, 80% of the plan’s funding will be based on this financial metric, while 20% of its funding will be based on an assessment of the Company’s progress against

38 2021 Aon Proxy Statement

quantitative goals within its I&D initiatives in the recruitment, promotion, education, and representation strategy pillars on a firm-wide basis, as determined by the Inclusion & Diversity Sub-Committee and the Organization & Compensation Committee. Further, individual leadership in championing I&D and other people and culture objectives will continue to be part of the annual performance assessment of each executive resulting in their award payment under the program after the funding framework has been applied.

Executive and Relocation Benefits

Executive Benefits. In addition to our broad-based employee benefit programs that are available to our employees generally (such as health coverage, 401(k) plan, etc.), each of our currently serving NEOs is eligible to participate in a deferred compensation program and a supplemental savings plan. Only Mr. Andersen participates in our defined benefit pension plan and the supplemental pension program because each other NEO was hired after the Aon Pension Plan was closed to new hires in 2004. Additional information regarding these qualified and nonqualified plan benefits is set forth under the headings “Pension Benefits in Fiscal Year 2020” and “Nonqualified Deferred Compensation in Fiscal Year 2020” contained in this proxy statement. We also provide an executive health screening program available to all of our NEOs and the other members of our senior management team.

Relocation Benefits. In 2020, we continued to provide relocation benefits resulting from the relocation of our headquarters to London, United Kingdom in 2012 (the “2012 Redomestication”) to certain of our NEOs. The Aon group global operating headquarters remained in London following the Company’s reorganization as a public company organized under the laws of Ireland in April 2020 (the “Reorganization”). The parent company Aon plc is resident in Dublin. Relocation benefits are customary for expatriate assignments for us and other employers in our industry. The Compensation Committee approved certain benefits for the relocated executives after consulting with FW Cook, and each relocated executive has signed an international assignment letter with Aon that sets forth the relocation benefits available to him or her. The relocation packages for our NEOs are intended to keep them “whole” on a total rewards basis, including with respect to any additional taxes incurred as a result of the relocation, be transparent and equitable, and reflect competitive practices and benchmarks of industry peers. The Compensation Committee periodically reviews the relocation packages of our executives. These benefits are provided pursuant to international assignment letters with our NEOs on assignment, which are described in more detail under the heading “International Assignment Letters.”

The compensation received in the form of such benefits is reflected in the Summary Compensation Table for Fiscal Years 2020, 2019, and 2018.

Post-Termination Compensation

We believe that providing severance and change in control severance benefits is important to recruit talented employees and secure the continued employment and dedication of our existing employees. A significant number of the companies with which we compete for talent have similar arrangements in place for their senior executives. While we consider these benefits to be important, the terms of these benefits are not considered as part of the compensation strategy when the Compensation Committee annually determines the compensation for the NEOs. Additional information about post-termination compensation is set forth in the section captioned “Potential Payments on Termination or Change in Control” contained in this proxy statement.

Severance Benefits Upon Change in Control. Our NEOs, other than Mr. Case, are eligible for change in control severance benefits under our Senior Executive Combined Severance and Change in Control Plan (referred to throughout this CD&A and the accompanying compensation tables as the “Combined Severance Plan”). The Combined Severance Plan provides that covered executives would receive certain severance benefits upon qualifying terminations of employment in connection with or within two years following a change in control of Aon. Thus, the Combined Severance Plan requires a “double trigger”—a qualifying change in control of Aon and a qualifying termination of the executive’s employment—for severance benefits to become payable. Mr. Case, who is not covered under the Combined Severance Plan, is party to an individual change in control severance agreement with the Company that also provides certain severance benefits upon a qualifying termination in connection with or within two years following a change in control of Aon. Neither the Combined Severance Plan nor Mr. Case’s individual agreement provides for excise tax gross-up protection in the event the executive becomes subject to tax under Section 280G of the Code in connection with such double trigger.

2021 Aon Proxy Statement 39

Additional information regarding the change in control arrangements for our NEOs is set forth in the section captioned “Potential Payments on Termination or Change in Control” contained in this proxy statement.

Severance Benefits Pursuant to Employment Agreements and Combined Severance Plan. We have entered into agreements with certain executive officers that provide for post-employment severance benefits and transitional compensation if the officer’s employment terminates for a qualifying event or circumstance unrelated to a change in control of Aon, such as being terminated without “cause,” as such term is defined in the operative agreement. To the extent that our NEOs are not party to an individual employment agreement providing for severance benefits, those individuals are eligible to receive severance benefits under the Combined Severance Plan. During 2020, each of our NEOs had an employment agreement providing for severance benefits or was eligible to receive severance benefits under the Combined Severance Plan. Additional information regarding such post-employment severance or transitional compensation for Mr. Case and the other NEOs is set forth in the section captioned “Potential Payments on Termination or Change in Control” contained in this proxy statement.

Tax Deductibility of Executive Compensation

Prior to the passage of the Tax Cuts and Jobs Act of 2017 (the “TCJA”) on December 22, 2017, Section 162(m) of the Internal Revenue Code of 1986, as amended (the “Code”), generally disallowed a tax deduction to publicly held companies for compensation paid to certain covered executive officers in excess of $1 million per officer, unless such compensation qualified as “performance-based.” Under the TCJA, the performance-based exception has been repealed with respect to taxable years beginning after December 31, 2017, subject to a special rule that “grandfathers” certain compensation paid pursuant to a written binding contract in effect as of November 2, 2017 that is not materially modified thereafter. As a result of the TCJA, most of the compensation paid to our current and certain former NEOs in excess of $1 million per officer in a year will not be deductible. While the TCJA may limit the deductibility of compensation paid to our NEOs, the Compensation Committee will—consistent with past practice—retain flexibility to design compensation programs that are in the best long-term interests of the Company and our shareholders.

Review of Compensation Policies and Practices

We believe that we maintain an appropriate level of prudence associated with our compensation programs and will continue to do so. We engage in a process to evaluate whether our executive and broad-based compensation programs contribute to unnecessary risk-taking, which includes an assessment by the Compensation Committee’s independent consultant of whether these programs create material risk. We have concluded that the risks arising from these programs are not reasonably likely to have a material adverse effect on the Company. In the first quarter of 2021, FW Cook assessed our executive compensation policies and practices and also concluded that they do not motivate imprudent risk-taking.

40 2021 Aon Proxy Statement

Executive Compensation

The executive compensation disclosure contained in this section reflects compensation information for the years ended December 31, 2020, December 31, 2019, and December 31, 2018 with respect to our NEOs for all years in which each NEO served in that capacity. The following Summary Compensation Table contains compensation information for the following NEOs: (1) Mr. Case, who served as our CEO during 2020, (2) Ms. Davies, who served as our Chief Financial Officer during 2020, and (3) Mr. Andersen, Mr. Bruno, and Mr. Goland, who were our three other most highly compensated executive officers serving as of December 31, 2020.

Summary Compensation Table for Fiscal Years 2020, 2019, and 2018



Name and Principal Position	Year		Salary (S)		Bonus ($)		Stock Awards ($)(1)		Option Awards ($)		Non-Equity Incentive Plan Awards ($)(2)		Change in Pension Value and Nonqualified Deferred Compensation Earnings ($)			All Other Compensation ($)(3)		Total ($)
Gregory C. Case		2020		1,500,000		—		15,880,566		—		2,242,500		—			671,430		20,294,496
Chief Executive		2019		1,500,000		—		13,705,798		—		—		—			802,045		16,007,843
Officer		2018		1,500,000		—		12,694,073		—		1,300,000		—			669,802		16,163,875
Christa Davies		2020		1,000,000		—		6,779,055		—		1,300,000		—			3,164,888		12,243,943
Executive Vice President		2019		975,000		—		5,024,842		—		—		—			1,739,576		7,739,418
and Chief Financial Officer		2018		900,000		—		4,375,050		—		1,040,000		—			6,003,119		12,318,169
Eric Andersen		2020		1,000,000		—		4,358,044		—		975,000		307,284			33,975		6,674,303
President (4)		2019		975,000		—		3,261,849		—		—		417,424			47,384		4,701,657
		2018		900,000		—		2,944,817		—		650,000		(143,864	)		44,355		4,395,308
John Bruno		2020		950,000		—		3,534,833		—		—		—			30,631		4,515,464
Chief Operating Officer (5)		2019		925,000		—		2,741,532		—		—		—			38,086		3,704,618
Anthony Goland		2020		900,000		—		2,878,451		—		380,250		—			—		4,158,701
Chief Innovation Officer

(#)	As part of the actions that we took to address COVID-19 and the resulting impact on our business, operations, and employees, each of our NEOs agreed to a temporary 50% reduction in his or her base salary from May 1, 2020 through November 1, 2020, at which time the foregone amounts were repaid.

(1)

The amounts shown reflect the aggregate grant date fair value (determined in accordance with Financial Accounting Standards Board Accounting Standards Codification Topic 718, Compensation—Stock Compensation (“ASC Topic 718”)) of restricted share unit awards (paid in satisfaction of 35% of each NEO’s annual incentive award for the previous performance year) and performance share unit awards granted to our NEOs pursuant to our Shareholder-Approved Plan in 2020, 2019, and 2018. These amounts disregard adjustments for forfeiture assumptions and do not reflect amounts actually paid to, or realized by, the NEOs in the years shown, or any prior years.

In 2018-2020, each of our NEOs received awards under the LPP with a grant date fair value as set forth in the table below.


Name	Year		Grant Date Fair Value of Performance Share Unit Awards Assuming Probable Outcomes Under LPP ($)		Grant Date Fair Value of Performance Share Unit Awards Assuming Achievement of Maximum Performance Levels Under LPP ($)
Gregory C. Case		2020		15,880,566		31,761,131
		2019		13,005,880		26,011,760
		2018		11,994,139		23,988,279
Christa Davies		2020		6,779,055		13,558,110
		2019		4,464,926		8,929,852

SEC Form DEF 14A filed by Aon plc