Ownership Submission
FORM 3
 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF 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 *
  CAMPBELL EILEEN M
 2. Date of Event Requiring Statement (Month/Day/Year)
06/01/2010		 3. Issuer Name and Ticker or Trading Symbol
MARATHON OIL CORP [MRO]
(Last)
(First)
(Middle)
C/O MARATHON OIL CORPORATION, 5555 SAN FELIPE ROAD		 4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Vice President, Public Policy
 5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

HOUSTON, TX 77056		 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 Beneficially Owned
1.Title of Security
(Instr. 4)		 2. Amount of Securities Beneficially Owned
(Instr. 4)		 3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)		 4. Nature of Indirect Beneficial Ownership
(Instr. 5)
Marathon Oil Corporation Common Stock 81,987.562
D
 

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)		 2. Date Exercisable and Expiration Date
(Month/Day/Year)		 3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)		 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)		 6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Stock Appreciation Right 05/26/2005 05/26/2014 Common Stock 64,200 $ 16.805 D  
Employee Stock Option (Right to Buy) 05/25/2006 05/25/2015 Common Stock 34,000 $ 23.825 D  
Employee Stock Option (Right to Buy) 06/01/2007 06/01/2016 Common Stock 15,200 $ 37.8175 D  
Employee Stock Option (Right to Buy) 05/30/2008 05/30/2017 Common Stock 15,600 $ 61.05 D  
Employee Stock Option (Right to Buy) 02/27/2009(1) 02/27/2018 Common Stock 16,500 $ 54.36 D  
Employee Stock Option (Right to Buy) 02/25/2010(2) 02/25/2019 Common Stock 27,000 $ 23.82 D  
Employee Stock Option (Right to Buy) 02/24/2011(3) 02/24/2020 Common Stock 32,600 $ 29.17 D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
CAMPBELL EILEEN M
C/O MARATHON OIL CORPORATION
5555 SAN FELIPE ROAD
HOUSTON, TX 77056		       Vice President, Public Policy  

Signatures

R. J. Kolencik, Attorney-in-Fact for Eileen M. Campbell 06/03/2010
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 5(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) Vests in three cumulative annual installments of 5,500, 5,500 and 5,500 shares on February 27, 2009, 2010, and 2011, respectively.
(2) Vests in three cumulative annual installments of 9,000, 9,000 and 9,000 shares on February 25, 2010, 2011, and 2012, respectively.
(3) Vests in three cumulative annual installments of 10,867, 10,867 and 10,866 shares on February 24, 2011, 2012, and 2013, respectively.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, See Instruction 6 for procedure.

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