<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

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    <periodOfReport>2006-08-17</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000101778</issuerCik>
        <issuerName>MARATHON OIL CORP</issuerName>
        <issuerTradingSymbol>MRO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001238373</rptOwnerCik>
            <rptOwnerName>MATHENY KENNETH L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MARATHON OIL CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>5555 SAN FELIPE ROAD</rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77056</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>V.P.-Investor Rel./Public Aff.</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

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                <value>COMMON STOCK</value>
            </securityTitle>
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                <value></value>
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                </transactionShares>
                <transactionPricePerShare>
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                </transactionPricePerShare>
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                    <value>A</value>
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                    <value>45522.0000</value>
                </sharesOwnedFollowingTransaction>
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                    <value>D</value>
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                </transactionShares>
                <transactionPricePerShare>
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                    <footnoteId id="F1"/>
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                    <value>31770.0000</value>
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                <directOrIndirectOwnership>
                    <value>D</value>
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                </transactionShares>
                <transactionPricePerShare>
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                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
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                    <value>31170.0000</value>
                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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        <nonDerivativeTransaction>
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                <value>COMMON STOCK</value>
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            <transactionDate>
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                <value></value>
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                </transactionShares>
                <transactionPricePerShare>
                    <value>86.62</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
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                <sharesOwnedFollowingTransaction>
                    <value>31070.0000</value>
                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>D</value>
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        <nonDerivativeTransaction>
            <securityTitle>
                <value>COMMON STOCK</value>
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            <transactionDate>
                <value>2006-08-17</value>
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                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionTimeliness>
                <value></value>
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            <transactionAmounts>
                <transactionShares>
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                </transactionShares>
                <transactionPricePerShare>
                    <value>86.61</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
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                </transactionAcquiredDisposedCode>
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                <sharesOwnedFollowingTransaction>
                    <value>29770.0000</value>
                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>D</value>
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        <nonDerivativeTransaction>
            <securityTitle>
                <value>COMMON STOCK</value>
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            <transactionDate>
                <value>2006-08-17</value>
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                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionTimeliness>
                <value></value>
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            <transactionAmounts>
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                    <value>3300.0000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>86.58</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
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            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>26470.0000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
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                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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        <nonDerivativeTransaction>
            <securityTitle>
                <value>COMMON STOCK</value>
            </securityTitle>
            <transactionDate>
                <value>2006-08-17</value>
            </transactionDate>
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                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3000.0000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>86.52</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>23470.0000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
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                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>COMMON STOCK</value>
            </securityTitle>
            <transactionDate>
                <value>2006-08-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>6558.0000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>86.46</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
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            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>16912.0000</value>
                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>EMPLOYEE STOCK OPTION (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>32.52</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-08-17</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>20310.00</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2002-05-29</value>
            </exerciseDate>
            <expirationDate>
                <value>2011-05-29</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>COMMON STOCK</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>20310.00</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
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                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>STOCK APPRECIATION RIGHT</value>
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                <value>32.52</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-08-17</value>
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                <transactionCode>M</transactionCode>
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                <transactionShares>
                    <value>20310.00</value>
                    <footnoteId id="F1"/>
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                    <value>0</value>
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                    <value>D</value>
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            </transactionAmounts>
            <exerciseDate>
                <value>2002-05-29</value>
            </exerciseDate>
            <expirationDate>
                <value>2011-05-29</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>COMMON STOCK</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>20310.00</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
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                <sharesOwnedFollowingTransaction>
                    <value>0.00</value>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
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            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Under the terms of the Stock Appreciation Right, the Stock Appreciation Right price is the highest fair market value of Marathon Oil Corporation common stock during the ten day trading period commencing August 4, 2006. The highest fair market value during such ten day trading period was $91.82.</footnote>
        <footnote id="F2">Exercise of tandem SAR and cancellation of underlying stock option.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>By: R. J. Kolencik, Attorney-in-Fact for Kenneth L. Matheny</signatureName>
        <signatureDate>2006-08-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0202
4
2006-08-17
0
0000101778
MARATHON OIL CORP
MRO
0001238373
MATHENY KENNETH L
C/O MARATHON OIL CORPORATION
5555 SAN FELIPE ROAD
HOUSTON
TX
77056
0
1
0
0
V.P.-Investor Rel./Public Aff.
COMMON STOCK
2006-08-17
4
M
0
20310.0000
32.52
A
45522.0000
D
COMMON STOCK
2006-08-17
4
D
0
13752.0000
91.82
D
31770.0000
D
COMMON STOCK
2006-08-17
4
S
0
600.0000
86.66
D
31170.0000
D
COMMON STOCK
2006-08-17
4
S
0
100.0000
86.62
D
31070.0000
D
COMMON STOCK
2006-08-17
4
S
0
1300.0000
86.61
D
29770.0000
D
COMMON STOCK
2006-08-17
4
S
0
3300.0000
86.58
D
26470.0000
D
COMMON STOCK
2006-08-17
4
S
0
3000.0000
86.52
D
23470.0000
D
COMMON STOCK
2006-08-18
4
S
0
6558.0000
86.46
D
16912.0000
D
EMPLOYEE STOCK OPTION (Right to Buy)
32.52
2006-08-17
4
M
0
20310.00
0
D
2002-05-29
2011-05-29
COMMON STOCK
20310.00
0.00
D
STOCK APPRECIATION RIGHT
32.52
2006-08-17
4
M
0
20310.00
0
D
2002-05-29
2011-05-29
COMMON STOCK
20310.00
0.00
D
Under the terms of the Stock Appreciation Right, the Stock Appreciation Right price is the highest fair market value of Marathon Oil Corporation common stock during the ten day trading period commencing August 4, 2006. The highest fair market value during such ten day trading period was $91.82.
Exercise of tandem SAR and cancellation of underlying stock option.
By: R. J. Kolencik, Attorney-in-Fact for Kenneth L. Matheny
2006-08-21