SEC Form DEFA14A filed by Trilogy Metals Inc.

How to Obtain Paper Copies of the Proxy Materials Securityholders may request to receive paper copies of the current meeting materials by mail at no cost. Requests for paper copies may be made using your Control Number as it appears on your enclosed Voting Instruction Form or Proxy. To ensure you receive the materials in advance of the voting deadline and meeting date, all requests must be received no later than May 2, 2025. If you do request the current materials, please note that another Voting Instruction Form/Proxy will not be sent; please retain your current one for voting purposes. For Holders with a 15 digit Control Number: Request materials by calling Toll Free, within North America - 1-866-962-0498 or direct, from Outside of North America - (514) 982-8716 and entering your control number as indicated on your Voting Instruction Form or Proxy. To obtain paper copies of the materials after the meeting date, please contact (604) 638-8088. For Holders with a 16 digit Control Number: Request materials by calling Toll Free, within North America - 1-855-638-8088 or direct, from Outside of North America - (604) 638-8088. To obtain paper copies of the materials after the meeting date, please contact (604) 638-8088. 0229SC Fold Fold Have questions about this notice? Call the Toll Free Number below or scan the QR code to find out more Toll Free – 1-866 964-0492 www.computershare.com/ noticeandaccess Notice of Availability of Proxy Materials for TRILOGY METALS INC. Annual General Meeting Meeting Date and Location: When: May 13, 2025 Where: Suite 901-510 Burrard St, Vancouver, BC 10:00 am (Pacific Time) You are receiving this notice to advise that the proxy materials for the above noted securityholders’ meeting are available on the Internet. This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. We remind you to access and review all of the important information contained in the information circular and other proxy materials before voting. The information circular and other relevant materials are available at: https://trilogymetals.com/investors/proxy-circular/ OR www.Sedarplus.ca TRILOGY METALS INC. CPUQC01.E.INT/000001/i1234

Voting PLEASE NOTE – YOU CANNOT VOTE BY RETURNING THIS NOTICE. To vote your securities you must vote using the methods reflected on your enclosed Voting Instruction Form or Proxy. PLEASE VIEW THE INFORMATION CIRCULAR PRIOR TO VOTING 0229TB Fold Fold Meeting Notice The resolutions to be voted on at the meeting are listed below along with the Sections within the Information Circular where disclosure regarding the matter can be found. 1. Election of Directors - Election of Directors 2. Appointment of Auditors - Appointment of Auditors 3. Approving Unallocated Entitlements under the Restricted Share Unit Plan - Approving Unallocated Entitlements under the Restricted Share Unit Plan 4. Approving Unallocated Entitlements under the Deferred Share Unit Plan - Approving Unallocated Entitlements under the Deferred Share Unit Plan 5. Non-Binding Advisory Vote on Executive Compensation - Non-Binding Advisory Vote on Executive Compensation Annual Financial statement delivery • No Annual Report (or Annual Financial Statements) is (are) included in this mailing