Smurfit Westrock plc

(a)Shareholder Proposals and Director Nominations

In accordance with Rule 14a-8 under the Exchange Act (“Rule 14a-8”) and the Amended Constitution of the Company (the

“Constitution”), the deadlines for the receipt of any shareholder proposals and director nominations to be considered at the Company’s

2025 Annual Meeting of Shareholders (the “2025 Annual Meeting”) are set forth below.

Any shareholder proposal submitted pursuant to Rule 14a-8 for inclusion in the Company’s proxy materials for the 2025

Annual Meeting must be received by our Group Company Secretary at our principal executive officesor by email at

AGM@smurfitwestrock.com no later than the close of business on December 19, 2024. Any such proposal also needs to comply with

the SEC shareholder proposal rules, including the eligibility requirements set forth in Rule 14a-8.

In addition, any shareholder seeking to nominate a director or to bring other business before the 2025 Annual Meeting outside

of Rule 14a-8 under the advance notice provisions included in the Constitution must provide timely notice, as set forth in the

Constitution. Specifically, written notice of any such proposed business or nomination must be received by our Group Company

Secretary at our principal executive officesor by email at AGM@smurfitwestrock.com no earlier than the close of business on

December 27, 2024 and no later than the close of business on January 26, 2025. Any notice of proposed business or nomination also

must comply with the notice and other requirements set forth in the Constitution and with any applicable law.

For purposes of shareholder proposals, the “close of business” shall mean 5:00 p.m. local time at the principal executive offices

of the Company in Dublin, Ireland, on any calendar day, whether or not the day is a business day.

(b)Material Changes to Procedures Related to Stockholder Recommendations of Director Candidates

Effective July 5, 2024, the Board of Directors of Smurfit Westrock adopted Principles of Corporate Governance, which set forth,

among other things, criteria for Board membership and provide that the Nomination Committee of the Board will consider director

candidates recommended by Company shareholders in accordance with the procedures that will be set forth in the proxy statement that

is expected to be filed within 120 days following the end of the Company’s fiscal year.

In addition, procedures for nominating directors are set forth in the Company’s amended constitution, which is filed as Exhibit 3.1

hereto. The deadlines for submission of any such nominations under the Company’s advance notice provisions include in the amended

constitution are set forth in Item 5(a) to this Quarterly Report on Form 10-Q and incorporated herein by reference.

(c)Trading Plans

In the three months ended September 30, 2024, none of our directors or officers (as defined in Rule 16a-1 under the Exchange

Act)adopted, modified orterminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement” (as those terms

are defined in Item 408 of Regulation S-K).