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: Arnold Colleen F. CIK: 0001409123 Role: Director --- Non-Derivative Transactions --- [Transaction #1] Security: Ordinary Shares Date: 2026-09-10 | Code: A (Grant or award) Shares: +343.768 | Price: $0.00 Shares Owned After: 36,622.748 | 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 4,537 restricted stock units which will vest on the earlier of (i) May 1, 2027, or (ii) the date of the next annual meeting of Smurfit Westrock plc's stockholders and 27,897.748 fully vested restricted stock units that will be settled in ordinary shares following the Reporting Person's cessation of service as a member of the Issuer's board of directors in accordance with the terms of the WestRock Company 2016 Deferred Compensation Plan for Non-Employee Directors. --- 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 4,537 restricted stock units which will vest on the earlier of (i) May 1, 2027, or (ii) the date of the next annual meeting of Smurfit Westrock plc's stockholders and 27,897.748 fully vested restricted stock units that will be settled in ordinary shares following the Reporting Person's cessation of service as a member of the Issuer's board of directors in accordance with the terms of the WestRock Company 2016 Deferred Compensation Plan for Non-Employee Directors. --- Signature --- /s/ /s/ Ciara O'Riordan, attorney-in-fact for Colleen F. Arnold (2026-09-14)