-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 oYxC+lLacFCDp72qZ8+jow==

<SEC-DOCUMENT>0000101778-04-000007.txt : 20040105
<SEC-HEADER>0000101778-04-000007.hdr.sgml : 20040105
<ACCEPTANCE-DATETIME>20040105120608
ACCESSION NUMBER:		0000101778-04-000007
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040102
FILED AS OF DATE:		20040105

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DAVIS WILLIAM L
		CENTRAL INDEX KEY:			0001012779

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	033-07065
		FILM NUMBER:		04502689

	BUSINESS ADDRESS:	
		STREET 1:		C/O R.R. DONNELLEY
		STREET 2:		77 WEST WACKER DRIVE
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60601

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MARATHON OIL CORP
		CENTRAL INDEX KEY:			0000101778
		STANDARD INDUSTRIAL CLASSIFICATION:	PETROLEUM REFINING [2911]
		IRS NUMBER:				250996816
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		P O BOX 3128
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77253-3128
		BUSINESS PHONE:		7136296600

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	USX CORP
		DATE OF NAME CHANGE:	19920703

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	UNITED STATES STEEL CORP/DE
		DATE OF NAME CHANGE:	19860714
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>
    <periodOfReport>2004-01-02</periodOfReport>
    <notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000101778</issuerCik>
        <issuerName>MARATHON OIL CORP</issuerName>
        <issuerTradingSymbol>MRO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001012779</rptOwnerCik>
            <rptOwnerName>DAVIS WILLIAM 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>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>
  <nonDerivativeTable>
   <nonDerivativeTransaction>
      <securityTitle>
          <value>COMMON STOCK</value>
      </securityTitle>
      <transactionDate>
          <value>2004-01-02</value>
      </transactionDate>
      <transactionCoding>
          <transactionFormType>4</transactionFormType>
          <transactionCode>A</transactionCode>
          <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionTimeliness>
      <value />
      </transactionTimeliness>
      <transactionAmounts>
          <transactionShares>
              <value>900.901</value>
          </transactionShares>
          <transactionPricePerShare>
              <value>33.30</value>
          </transactionPricePerShare>
          <transactionAcquiredDisposedCode>
              <value>A</value>
          </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <postTransactionAmounts>
          <sharesOwnedFollowingTransaction>
              <value>5625.550</value>
              <footnoteId id="F1" />
          </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
          <directOrIndirectOwnership>
              <value>D</value>
          </directOrIndirectOwnership>
      </ownershipNature>
   </nonDerivativeTransaction>
  </nonDerivativeTable>
  <derivativeTable>
  </derivativeTable>
<footnotes>
   <footnote id="F1">Includes dividends of 94.571 shares previously not reported pursuant to Rule 16a-11.</footnote>
</footnotes>
<remarks></remarks>    <ownerSignature>
       <signatureName>R. J. Kolencik, Attorney-in-Fact for William L. Davis</signatureName>
       <signatureDate>2004-01-05</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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