2026 Definitive Proxy Statement & Notice of AGM

Smurfit Westrock plc

(the ‘Company’)

11 March 2026

2026 Definitive Proxy Statement, Annual Report to Security Holders and Additional Definitive Proxy Soliciting Material

Smurfit Westrock plc today filed the:

• 2026 Definitive Proxy Statement for the Company’s 2026 Annual General Meeting of Shareholders on Schedule 14A with the U.S. Securities and Exchange Commission (the “SEC”);
• Annual Report to Security Holders for the fiscal year ended December 31, 2025 on Form ARS with the SEC (the “2025 Annual Report”); and
• Additional Definitive Proxy Soliciting Material.

(together, the “Proxy Materials”).

The Proxy Materials have been filed with the SEC in accordance with the U.S. Securities Exchange Act of 1934, as amended, and are available to view on:

• the SEC's website at: https://www.sec.gov; and

• the Company's website at: https://investors.smurfitwestrock.com/general-meetings/agm

The 2026 Definitive Proxy Statement and the 2025 Annual Report have also been submitted to the U.K. National Storage Mechanism and will shortly be available for inspection at: https://data.fca.org.uk/#/nsm/nationalstoragemechanism

The Company’s Irish Statutory Annual Report for the year ended December 31, 2025, as required under Irish law, was also published by the Company today and is available to view on the Company's website at: https://investors.smurfitwestrock.com/general-meetings/agm

Contact

Gillian Carson-Callan

Group SVP Finance & Company Secretary

T: +353 1 202 7000

View source version on businesswire.com: https://www.businesswire.com/news/home/20260310982328/en/

Smurfit Westrock plc