Smurfit Westrock (SW)

=== SEC Form 4 — Statement of Changes in Beneficial Ownership === Document Type: 4 Period of Report: 2026-09-10 10b5-1 Pre-arranged Plan: No --- Issuer --- Name: Smurfit Westrock plc (SW) CIK: 0002005951 --- Reporting Owner --- Name: Mayer Saverio CIK: 0002028256 Role: Officer (See remarks) --- Non-Derivative Transactions --- [Transaction #1] Security: Ordinary Shares Date: 2026-09-10 | Code: A (Grant or award) Shares: +119 | Price: $0.00 Shares Owned After: 241,684 | Ownership: D (Direct) Footnotes: [F1] In accordance with the terms of the restricted stock unit award, additional restricted stock units accrued as dividend equivalents in connection with the Issuer's payment of a quarterly dividend of $0.4523 per ordinary share. Such additional restricted stock units are subject to the same terms and conditions as the underlying award. Each restricted stock unit represents the right to receive one ordinary share. [F2] Includes 32,704 restricted stock units which are scheduled to vest in three equal annual installments beginning on the first anniversary of the grant date. --- Derivative Transactions --- [Transaction #1] Security: Restricted Stock Units (PSP) Date: 2026-09-10 | Code: A (Grant or award) Shares: +403 | Price: $0.00 Exercise Price: $0.00 Shares Owned After: 38,054 | Ownership: D (Direct) Footnotes: [F1] In accordance with the terms of the restricted stock unit award, additional restricted stock units accrued as dividend equivalents in connection with the Issuer's payment of a quarterly dividend of $0.4523 per ordinary share. Such additional restricted stock units are subject to the same terms and conditions as the underlying award. Each restricted stock unit represents the right to receive one ordinary share. [F3] The 38,054 restricted stock units vest and are due to settle in February 2027. [F3] The 38,054 restricted stock units vest and are due to settle in February 2027. --- Footnotes (Complete Index) --- F1: In accordance with the terms of the restricted stock unit award, additional restricted stock units accrued as dividend equivalents in connection with the Issuer's payment of a quarterly dividend of $0.4523 per ordinary share. Such additional restricted stock units are subject to the same terms and conditions as the underlying award. Each restricted stock unit represents the right to receive one ordinary share. F2: Includes 32,704 restricted stock units which are scheduled to vest in three equal annual installments beginning on the first anniversary of the grant date. F3: The 38,054 restricted stock units vest and are due to settle in February 2027. --- Signature --- /s/ /s/ Ciara O'Riordan (attorney-in-fact for Saverio Mayer) (2026-09-14)