Kosmos Energy Ltd.

2026 Virtual Annual Stockholders Meeting

These proxy materials are being furnished to you in connection with the solicitation of proxies by the Board of Directors of Kosmos Energy Ltd. for use at the 2026 annual stockholders meeting and any adjournments or postponements thereof. We refer to our Board of Directors as the “Board” and to Kosmos Energy Ltd. as “Kosmos,” the “Company,” “we” or “us.” The annual stockholders meeting will be held virtually on Thursday, May 28, 2026 beginning at 8:00 a.m., Central Daylight Time. You will be able to attend the meeting virtually, vote your shares electronically, and submit your questions during the meeting by visiting:

www.virtualshareholdermeeting.com/KOS2026

The items to be considered are summarized in the Notice of Virtual Annual Stockholders Meeting and more fully described in this Proxy Statement. The Notice of Virtual Annual Stockholders Meeting, this Proxy Statement, the enclosed Proxy Card and our 2025 Annual Report on Form 10-K are first being mailed and made available starting on or about April 16, 2026 to all record holders of our common shares as of the close of business on March 30, 2026. Our common shares represented by proxies will be voted as described below or as specified by each stockholder.

Stockholders will need the control number included on their notice of internet availability, proxy card or voting instruction form to be admitted to the virtual meeting as a stockholder, vote their shares and ask questions.