6APR201207345158 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ፤ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2017 អ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-35167 Kosmos Energy Ltd. (Exact name of registrant as specified in its charter) Bermuda 98-0686001 (State or other jurisdiction of (I.R.S. Employer incorporation or organization) Identification No.) Clarendon House 2 Church Street Hamilton, Bermuda HM 11 (Address of principal executive offices) (Zip Code) Registrant’s telephone number, including area code: +1 441 295 5950 Securities registered pursuant to Section 12(b) of the Act: Title of each class Name of each exchange on which registered: Common Shares $0.01 par value New York Stock Exchange London Stock Exchange Securities registered pursuant to Section 12(g) of the Act: None Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ፤ No អ Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes អ No ፤ Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ፤ No អ Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes ፤ No អ Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K (§229.405 of this chapter) is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. ፤ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of ‘‘large accelerated filer,’’ ‘‘accelerated filer,’’ ‘‘smaller reporting company’’ and ‘‘emerging growth company’’ in Rule 12b-2 of the Exchange Act. Large accelerated filer ፤ Accelerated filer អ Non-accelerated filer អ Smaller reporting company អ Emerging growth company អ (Do not check if a smaller reporting company) If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. អ Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes អ No ፤ The aggregate market value of the voting and non-voting common shares held by non-affiliates, based on the per-share closing price of the registrant’s common shares as of the last business day of the registrant’s most recently completed second fiscal quarter was $1,462,148,287. The number of the registrant’s Common Shares outstanding as of February 16, 2018 was 395,706,528. DOCUMENTS INCORPORATED BY REFERENCE Part III, Items 10-14, is incorporated by reference from the Proxy Statement for the Annual Meeting of Shareholders which will be filed with the Securities and Exchange Commission not later than 120 days subsequent to December 31, 2017. Certain exhibits previously filed with the Securities and Exchange Commission are incorporated by reference into Part IV of this report.