Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
Hayes William S
  2. Issuer Name and Ticker or Trading Symbol
Kosmos Energy Ltd. [KOS]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Senior V.P. & General Counsel
(Last)
(First)
(Middle)
C/O KOSMOS ENERGY, LLC, 8176 PARK LANE, SUITE 500
3. Date of Earliest Transaction (Month/Day/Year)
05/16/2011
(Street)

DALLAS, TX 75231
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Shares 05/16/2011   J(1)(2)   839,267 A $ 0 (1) (2) 839,267 D  
Common Shares 05/16/2011   P   1,500 A $ 18 (3) 840,767 D  
Common Shares 05/18/2011   A(4)   705,882 A $ 0 (4) 1,546,649 D  

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Common Shares (Right to Receive) (5) 05/18/2011   A   176,471     (6)   (6) Common Shares 176,471 $ 0 (6) 176,471 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Hayes William S
C/O KOSMOS ENERGY, LLC
8176 PARK LANE, SUITE 500
DALLAS, TX 75231
      Senior V.P. & General Counsel  

Signatures

 /s/ Phillip Feiner, as Attorney-in-Fact   05/18/2011
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) In connection with a corporate reorganization, which involved Kosmos Energy Holdings becoming wholly-owned by the Issuer, and the Issuer's initial public offering described in the prospectus dated May 11, 2011, the reporting person received 290,964 common shares in exchange for his vested units in Kosmos Energy Holdings, the Issuer's predecessor, and 548,303 restricted shares in exchange for his unvested profit units in Kosmos Energy Holdings under the Issuer's Long Term Incentive Plan (the "Plan"). Subject to the terms of the Plan and an award agreement under the Plan, these restricted shares are scheduled to vest on the same dates as the exchanged profit units were scheduled to vest, as follows:
(2) 83,039 of these restricted shares are scheduled to vest on October 11, 2011, 38,742 shares of these restricted shares are scheduled to vest on June 11, 2012, 53,726 of these restricted shares are scheduled to vest on December 10, 2012, and 372,796 of these restricted shares are scheduled to vest 50% on December 9, 2012 and 50% on December 9, 2014.
(3) The price to the public in the Issuer's initial public offering.
(4) These restricted shares were granted under the Plan and are scheduled to vest 25% on each of the first four anniversaries of May 16, 2011, subject to the terms of the Plan and an award agreement under the Plan.
(5) 1 for 1.
(6) In connection with the Issuer's initial public offering, the reporting person acquired a contractual right to receive restricted shares under the Plan within 30 days after the offering. These restricted shares are scheduled to vest 25% on each of the first four anniversaries of May 16, 2011 based on the satisfaction of certain performance conditions, in accordance with the terms of the Plan and an award agreement to be issued under the Plan.

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