UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

(Amendment No. )

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Filed by a Party other than the Registrant ☐

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☐ Preliminary Proxy Statement

☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

☐ Definitive Proxy Statement

☒ Definitive Additional Materials

☐ Soliciting Material under §240.14a-12

Organon & Co.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

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Your Vote Counts! ORGANON & CO. 2024 Annual Meeting Vote by June 3, 2024 11:59 PM Eastern Daylight Time ORGANON & CO. 30 HUDSON STREET FLOOR 33 JERSEY CITY, NJ 07302 V35197-P04602 You invested in ORGANON & CO. and it’s time to vote! You have the right to vote on proposals being presented at the Annual Meeting. This is an important notice regarding the availability of proxy materials for the shareholder meeting to be held on June 4, 2024. Get informed before you vote View the Notice and Proxy Statement and Annual Report online OR you can receive a free paper or email copy of the material(s) by requesting prior to May 21, 2024. If you would like to request a copy of the material(s) for this and/or future shareholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to sendmaterial@proxyvote.com. If sending an email, please include your control number (indicated below) in the subject line. Unless requested, you will not otherwise receive a paper or email copy. For complete information and to vote, visit www.ProxyVote.com Control # Smartphone users Vote Virtually during the Meeting Point your camera here and June 4, 2024 9:00 AM Eastern Daylight Time vote without entering a control number Virtually at: www.virtualshareholdermeeting.com/OGN2024 *Please check the meeting materials for any special requirements for meeting attendance.

Vote at www.ProxyVote.com THIS IS NOT A VOTABLE BALLOT This is an overview of the proposals being presented at the upcoming shareholder meeting. Please follow the instructions on the reverse side to vote these important matters. Board Voting Items Recommends 1. Election of Directors Nominees: 1a. Kevin Ali For 1b. Martha E. McGarry For 1c. Philip Ozuah, M.D., Ph. D. For 1d. Shalini Sharp For 2. Approve, on a non-binding advisory basis, the compensation of Organon’s Named Executive Officers. For 3. Ratify the appointment of PricewaterhouseCoopers LLP as Organon’s independent registered public accounting firm For for 2024. NOTE: The proxies are authorized to vote in their discretion upon such other business as may properly come before the meeting or any adjournment or postponement thereof. Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click “Delivery Settings”. V35198-P04602