SEC Form 6-K filed by KT Corporation

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16

OF THE SECURITIES EXCHANGE ACT OF 1934

For the month of November 2025

Commission File Number 1-14926

KT Corporation

(Translation of registrant’s name into English)

90, Buljeong-ro,

Bundang-gu, Seongnam-si,

Gyeonggi-do,

Korea

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

Form 20-F ☒   Form 40-F ☐

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

KT Corporate Value-Up Plan 2025.11 KT Corporation kt

Disclaimer This presentation has been prepared by KT Corp. (“the Company”) to explain the Corporate Value-Up Plan. All information regarding the Company’s management and financial performance has been prepared in accordance with K-IFRS standards. This presentation contains forward-looking statements, which are subject to risks, uncertainties, and assumptions. This presentation is being presented solely for your information and is subject to change without notice. The Company does not guarantee the accuracy or completeness of such forward-looking statements and assumes no obligation to update this document for future developments or new information. If you have any questions related to this material, please contact the IR department. Tel: +82-70-4193-4036 2

[Executive Summary] | FY2028 Financial Target and Action Plans 2028 Target AICT Transformation AICT Company kt AI/IT Rev. Share Up 3x of 2023 Attain top-tier Al/Cloud capabilities by global big tech partnership Progress [2024~3Q25 YTD] Strengthened AX capability with strategic partnership (Al model SOTAK, Palantir partnership) Strategy Consolidated ROE 9% ~ 10% Secure Profitability Consolidated OP Margin 9% Enhance OP through streamlining low-profit biz Improved business and cost structure (Low-margin 39 biz, KRW 50bn) Asset Optimization Non-Core Asset Liquidation Liquidate non-core assets and idle real estate Liquidated non-core assets (Profit KRW82.4bn, Cash KRW275.7bn) Additional Shareholder Return KRW 1tr. Share Buyback Enhance capital efficiency through additional returns ‘25 Share buyback KRW 250bn (Cancellation will be executed considering foreign ownership limit) Integrate Al into core biz. Telco, Media, NW, IT, accelerate growth of B2B AX and revamp mgmt. structure 3

Contents 1 Company Overview 2 Progress & Analysis 3 Target & Action Plan 4 ESG/IR Activities 4

Company Overview Name of Company KT Corporation CEO Young-Shub Kim LCompany Overview IL Progress & Analysis IL Target&Action Plan IV.ESG/IRActivities Business Overview KT Separate revenue KRW 18,579.7bn (FY2024) Subsidiaries’ revenue KRW 13,256.2bn No. of Employees 14,512 (as of 25.06.30, KT Separate) Industry Date of Incorporation Date of KOSPI Listing No. of Subsidiaries Credit Rating ESG Rating Telecommunications December 10, 1981 December 23, 1998 78 (Excluding KT) (As of ‘25.6.30) A- (S&P), A3 (Moody’s), A (Fitch), AAA(KIS Rating), AAA(Korea Rating) A+ (KCGS**), AA (Sustinvest) A (Korea ESG Research Institute) *Subsidiaries’ revenue share excludes internal transactions **KCGS: Korea Institute of Corporate Governance and Sustainability Wireless M/S no2(w/319%) Wireless 26.3% BC Card Broadband M/S no.1(w/44%) Broad- kt skylife band 26,431.2 Subsi 9.4% IPTV bn KRW Media diaries* 29.7% StudioGenie M/S no.1(w/43%) 7.9% ktestatę B2B B2B 13.5% others 13.2% kt cloud Corporate clatinesM/S not 5

L.Company Overview II. Progress & Analysis III. Target & Action Plan IV.ESG/IRActivities Shareholder Composition as of Jun. 30, 2025 Total issued shares: 252,021,685 Domestic institutions and Individuals 28.67% NPS 754% Hyundai Motor Group 8.07% TreasuryShares 3.95% Board Composition General Shareholders’ Meeting BoD 8 Outside dir. 2 Inside dir. CEO *ESOP: Employee Stock Ownership Plan ForeignInvestors 49.00% KT Corporate Governance Model Transparent and independent governance structure led by the Board of directors Independence of BoD ESOP* 2.77% BoardCommittees Corporate Governance Audit Evaluation and Compensation ESG 4 Outside directors 5 Outside directors 4 Outside directors 4 Outside & 1 Inside directors Director Candidate 8 Outside Recommendation directors 4 Outside & Investment **DCRC: Director Candidate Recommendation Committee 1 Inside directors Enhancement of Shareholder Value Responsible Management of Professional Executive Independence in Board compositionand operation Transparency in appointment process of outside directors Special authority to outside directors Shareholder Retum ShareholderRights Shareholder Protection CEO Appointmentand Management Contract Remunerationand others ▪ 80% of outside directors, and separation of CEO and chairman ● Corporate Governance, Audit, Evaluation and Compensation, and Director Candidate Recommendation committeesare composed of all outside directors Operation of Director Candidate Recommendation Committee Utilization of Professional Institutions for evaluating candidates ● Assessment of CEO managementcontracts and recommendation for CEO dismissal ● Determination of CEO and inside directors’ compensation ● Implementation of share buybacks/cancellations and quarterly dividends ● Adoption of cumulative and written&electronic voting ●Timely disclosure of corporate information Controlofinternaltransactions and self-dealing ● CEO candidate recommended by BoD and DCRC**, and appointed by shareholder resolution The BoDenters into a managementcontract with appointed CEO and conducts an annual performanceevaluation CEO compensation basedonmanagement performance 6

Contents 1 Company Overview 2 Progress & Analysis 3 4 Target & Action Plan ESG/IR Activities 7

Market evaluation LCompany Overview IL Progress & Analysis III. Target& Action Plan IV.ESG/IRActivities AICT transformation and value-up plan drove 55% market cap growth(as of Sep. 30) compared to early 2023, with ownership remaining full at 49% IKT’s MarketCap. Trends Market cap KRW 8.5tr (Jan. 2, 2023) Foreign ownership 43% (Dec. 2023) Jan. 2023 Market cap KRW 14.7tr (Jul. 15, 2025) QPalantir Strategic Partnership (Jun. 5, 2025) Disclosure of KT’s Value-up Plan (Nov 5, 2024) Awarded as an Excellent Value-up company (‘25.5.27) Declaration of AICT Company Strategy Microsoft Strategic Partnership (Feb. 28, 2024) (Sep. 27, 2024) Appointment of CEO Inclusion into KRX’s Korea Value-up Index (‘24.12.16) Kim Young-shub (Aug. 30, 2023) Foreign ownership limit of 49% reached(Nov. 5, 2024) Jan. 2024 * Stock price (closing) from 2023 to 2025: highest KRW 58,400 (July 15, 2025), lowest KRW 29,000 (January 16, 2023) Jan. 2025 Sep. 2025 8

LCompany Overview IL Progress & Analysis ILTarget&Action Plan IV.ESG/IRActivities Financial KT continued stable profit growth through business structure optimization, including AICT Performance restructuring and streamlining of low-profit/non-core businesses Revenue Operating Profit Net Profit Con. (KRW tr) (KRW tr) (KRW tr) 25.7 26.4 26.4 2.24 21.4 1.75 1.69 1.76 1.65 1.39 1.09* 0.99 0.81 0.4 2022 2023 2024 25.30 2022 2023 2024 25.30 2022 2023 2024 25.3Q Sep. (KRW tr) (KRW tr) (KRW tr) 18.3 18.4 18.6 1.30* 1.17 1.19 1.21 1.10* 14.6 1.01 0.93 0.76 0.35 0.33 2022 2023 2024 25.30 2022 2023 2024 25.3Q 2022 2023 2024 25.3Q *Excluding one-off costs (approx. KRW 1tr) 9

Value-up Progress I.Company Overview IL Progress & Analysis III. Target&Action Plan IV.ESG/IRActivities Excluding one-off expenses in 2024, consolidated ROE is 6.9%; KT aims for 9-10% mid-term ROE by increasing the share of AI/IT revenue, enhancing profitability, and improving capital efficiency FY2024 ROE 6.9%*(2.9%) Consolidated OP Margin |AI/IT Revenue% (KRW tr) FY2023 ROE 6.1% Target More than 19%** Additional Share buybacks/Cancellations (KRW tr) Target Total KRW 1tr Target 9% 10.5% 6.7% 6.3% 3.1% 0.0 0.0 0.25 ‘25.3Q ‘28(T) ‘23 ‘24 ‘25.3Q ‘28(T) ‘23 ‘24 ‘25.3Q ‘28(T) ** as a portion of service revenue on a KT separate basis 1.1 1.0 0.9 7% 6% 7% ‘23 ‘24 *Excluding one-off costs (approx. KRW 1tr) 10

LCompany Overview LProgress & Analysis IIL Target&Action Plan IV.ESG/IRActivities Valuation Metrics PER Although PER, PBR, and ROE have all shown an improving trend in 2024, the company remains undervalued compared to domestic peers and the KOSPI | PBR PER has shown a positive trend; however, the stock continues to trade relatively at a discount Although PBR improved by 20% in 2024, KT remains undervalued relative to its net asset value (PBR at 1x) ROE ROE has underperformed relative to peers and KOSPI Shareholder Retum ratio* Shareholder return ratio is around 50%, slightly below the level of domestic peers 110.3% 58.1% 37.6% Recent 3-year Avg. 23.0 (FY’22~FY’24) 0.7 8.0% ** 6.9% 6.1% 6.5 8.5 ..O 0.5 0.5 KT 9.6* 2.9% 2022 2024 2022 2024 2022 2024 2022 Recent 3-year Avg. (FY’22~FY’24) 9.5 13.8 0.9 8.3 0.7 7.0 9.5 0.6 ** 8.2 ** 45.2% 2024 62% 47% KT Peers KOSPI KT Peers KOSPI KT Peers KOSPI KT Peers * Source : Bloomberg(PER,PBR), KRX Market Data System(ROE) *Shareholder return ratio: (Cash dividends + Share buybacks/cancellations)/Consolidated net income attributable to owners of the Parent company ** excluded one-off expenses(of about KRW 1 tr) in 2024 11

1. Company Overview IL Progress & Analysis III.Target&Action Plan I.ESG/IR Activities ROE Analysis COE, reflecting market expected return, is in the range of 9%-10%, while ROE excluding one-offs in 2024 stands at 6.9%; ROE has been improving since value-up plan but remains below the COE | ROE-COE Analysis ROE remains lower than the COE COE 9%~10% 9.4%** 7.7% 7.5% 8.0%** 6.9%* 6.1% Avg. ROE 6.5% 6.1% 4.1% 5.0% 4.5% 2015 2018 2021 2024 |Value-up direction ROE 6.9% PBRQ.7X COE9%~10% Corporate value can be enhanced by improving ROE through measures such as strengthening profitability and optimizing capital efficiency *Excluding one-off costs (approx. KRW 1tr) **Reflecting one-off gains: KRW 362.4 bn from REITs sales and dividend income in 2021, and KRW 215.7 bn from ‘Seezn’ sales in 2022 12

Contents 1 Company Overview 2 Progress & Analysis 3 Target & Action Plan 4 ESG/IR Activities 13

Target Setting I.Company Overview II. Progress & Analysis III. Target&Action Plan IV.ESG/IRActivities 2028 ROE target remains at 9%~10% considering cost of equity(COE), Sustain AI/IT growth, margin improvement, asset sales, and buybacks to achieve ROE target Valueenhancement direction 2028 Target ROE 9% ~10% Enhance value by achieving ROE above COE AICT Transformation AI/IT rev. share up 3x of 2023 2024 *ROE 6.9% Margin Improvement Asset Monetization Consolidated OP margin 9% Non-core asset liquidation Enhancing Plan ROA (Net income/Assets) NetMargin (Net income/Sales) Asset Tumover (Sales/Assets) Financial 2023 ROE 6.1% Shareholder Return Share buybacks/cancellationKRW 1tr Leverage (Assets/Equity) *Excluding one-off costs (approx. KRW 1tr) 14

I.Company Overview II. Progress & Analysis III. Target & Action Plan IV.ESG/IR Activities AICT Transform Enhancing AI/IT capabilities and driving AICT transformation via global big tech partnerships and IT modernization AICT Transformation AI/IT Rev. Share Up 3x of 2023 |AI/IT Sales Contribution* Strategic Direction Target 19% over 6% 7% (1.0tr) (1.1tr) Expanding industry-specific Al services through partnerships with global big tech companies FY25 Performance Microsoft Launched SOTA K, QPalantir Deployed Al platform at KT an its domestic distribution | Korea AX Market Outlook** 29.6 (Unit: KRW tr) 26.5 23.3 20.1 17.5 14.5 2023 2024 2025(E) *AI/IT Sales Contribution based on KT separate service rev. 2026(E) 2027(E) 2028(E) Public Identifying new opportunities aligned with national Al/Cloud policy Finance Developing the financial sector’s Al adoption with specialized Al agents Corp. · Providing tailored Al consulting and models via KT-MS Al experts *Source: IDC Korea, “Korea Big Data and Analytics Forecast” (23.04), “Whole Cloud Forecast” (24.08) 15

I.Company Overview II. Progress & Analysis III. Target& Action Plan I.ESG/IRActivities Complete a growth-oriented business portfolio by 2028 through AICT transformation and streamlining of low-profit businesses Streamline low-margin businesses Margin Improvement | Consolidated OPM 6.7%* 6.3% Consolidated OP Margin 9% Strategic Direction Target 9% over 2023 2024 2025(E) 2026(E) 2027(E) 2028(E) Continue rationalization for margin improvement Target Low-profit biz with limited potential · High-cost biz without competency . Biz with low value for AICT FY25Performance Streamlined 23 businesses with low growth potential, limited competences—Healthcare, Logistics solutions, Solar energy, etc. Revamped profit model of 16 businesses—Smart city, AICC, C-ITS, etc. *Excluding one-off costs (approx. KRW 1tr) Action Cease operation by 2025 (No revenue or costs from 2026) · Gradual exit by contract terms Impact Improving OP of KRW 50bn in 2025 16

LCompany Overview IL Progress & Analysis IL Target& Action Plan M.ESG/IRActivities Enhance asset efficiency through telecom facility optimization and monetization of non-core real estate Monetizing non-core real estate Asset Efficiency Asset Monetization Status of Real Estate Assets (KT and kt estate book value) Strategic Direction Ongoing monetization of non-core real estate assets Book value 4.6tr Develop or divest assets based on feasibility Non-telco 2.3tr (51%) 42 assets 41 assets 43 assets Result Sales of small idle properties (A1) (+2) Unlock idle assets via telco sites optimization Cash-in Telco Profit 2.3tr 379 Corp mgmt. (49%) assets 377 assets 376 assets (A2) (A1) 62.5bn 79.6bn 3Q25 2023 2024 3Q25 2024~3Q25 YTD 17

I.Company Overview II. Progress & Analysis III. Target&Action Plan I.ESG/IR Activities Asset Efficiency Monetize investment assets considering purpose, profitability, and strategic value, and use proceeds for capital allocation Asset Monetization Divestment of Non-essential Investment Assets Status of Investment Assets Strategic Direction (KT standalone book value) Ongoing portfolio optimization based on strategic/financial value Book value 6.6tr Sell marketable securities with diminished strategic relevance Marketable 2.2tr Securities (34%) 60 holdings 56 holdings 52 holdings Result · A8 marketable securities (A4) (A4) · A5 subsidiaries (6 new, 7 sold, 2 merged, 2 liquidated) Optimize group portfolio for sustainable growth Cash-in Investments in 4.4tr Profit Subsidiaries (66%) 84 holdings 83 holdings 79 196.2bn holdings 19.9bn (A1) (A4) 3Q25 2023 2024 3Q25 2024~3Q25 YTD 18

Capital Allocation LCompany Overview Progress & Analysis IL Target&Action Plan IV.ESG/IR Activities Boost free cash flow via profits from AICT transformation and non-core asset sales; invest KRW 1trFY25~28 in buybacks/cancellations, and strategic investments to enhance ROE AICT Transformation FY’25~28 OCF Asset Sales CAPEX (incl. tangible and intangible asset investments) FY 25~28 Additional Shareholder Return In progress Shareholder Return (based on shareholder return policy) Capital Allocation Direction Share buyback/cancellation KRW 1tr Investments to improve ROE FY’25~‘28 FCF review -Scale for ROE impact—AICT-aligned synergy 19

Contents 1 Company Overview 2 Progress & Analysis 3 Target & Action Plan 4 ESG/IR Activities 20

Governance LCompany Overview IL Progress & Analysis III. Target & Action Plan IV.ESG/IRActivities Improve processes to establish stable governance structure and strengthen the Board’s role in enhancing corporate value Enhancing Director Appointment Process Ensuring Fairness and Transparency in CEO & Outside director appointment process Direction Achieve Top-tier compliance system Strengthen Transparent management and Corporate governance Reinforce KT Group-wide compliance system ● Review and selection of director candidates by the Director Candidate Recommendation Committee, composed entirely of outside directors Stricter CEO appointment requirements approval of more than 3/5 voting rights present than provisions in the Commercial Act Strengthening Internal Control Group-wide compliance and risk management .Establish and operate an integrated risk management system across KT group -Enhance the identification and inspection of key areas with high compliance risk related to operations Responsible management and Corporate value-up by the Board of Directors Enhancing the role of the Board -Promote amendments of the AOI reflecting revisions of the Commercial Act, including the expansion of directors’ duty of loyalty ●Conduct periodic reviews of Value-up plan and determine shareholder returns considering cashflow and market expectations Strengthen the Board’s deliberation function on major capital allocations 21

LCompany Overview IL Progress & Analysis ILTarget& Action Plan IV.ESG/IRActivities Social/ Provide a secure and reliable network environment through stronger information security and Environment management; achieve Net Zero by 2050 as a responsible corporate citizen Enhance information security and Social Network management Environment AICT-driven environmental leadership Information Security—Invest KRW 1tr over 5 years for security enhancement -Reinforce zero-trust and Al-based monitoring -Increase security workforce through global partnerships ●Continuously reinforce core security frameworks 2050 Net Zero-RE100 Renewable Energy Target 84% Renewable Energy 100% 56% 0% Carbon Emissions Net zero Network Management -IT/NW infra penetration tests and fix vulnerabilities ● Address structural issues in NW security architecture—Establish integrated IT/NW security roadmap Carbon Neutrality 2021 2030(E) 2040(E) 2050(E) Transition to Renewable Energy and Improve Energy Efficiency Climate Green Innovation & Climate Management Capability Across Value Chain 22

IR Activities LCompany Overview IL Progress & Analysis III Target& Action Plan IV.ESG/IRActivities Broaden communication with shareholders and market, and improve investor access through transparent, timely disclosures | 2025 Key IR Activities Capital Market Communication Date Major Activities Nov ‘24 Mar ‘25 Released “KT Corporate Value-up Plan. Hosted AGM with online broadcast May 25 Hosted ‘KT Corporate Day’ led by the CEO Jul ‘25 Sep 25 Nov ‘25 Events 2022 2023 2024 Shareholders’ meeting(AGM/EGM) 1 3 1 Earnings release 4 4 4 IR meetings 318 311 303 KT Corporate Day CEO-led 1 1 1 1 1 2 Domestic disclosures 72 74 66 Overseas disclosures US NYSE, Japan 31 44 42 Released ‘Progress Report: KT Corporate Value-up Plan’ Awarded as an ‘Excellent Value-Up Company’ by KRX Hosted ‘KT Group IR’ event Participated in ‘KCMC 2025’ conference hosted by KRX Reviewed and released ‘KT Corporate Value-up Plan’ KT Group IR IR Comm. Direction Board IR Strengthen Board-led communication Continue IR activities domestic/overseas Mgmt Disclosure Strengthen Management-led IR comm. Timely information sharing 23

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