-----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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 tVZeKUtmL+ZCqe3IDD90TQ==

<SEC-DOCUMENT>0001027724-07-000005.txt : 20070518
<SEC-HEADER>0001027724-07-000005.hdr.sgml : 20070518
<ACCEPTANCE-DATETIME>20070518154227
ACCESSION NUMBER:		0001027724-07-000005
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20070516
FILED AS OF DATE:		20070518
DATE AS OF CHANGE:		20070518

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SOUTHWEST AIRLINES CO
		CENTRAL INDEX KEY:			0000092380
		STANDARD INDUSTRIAL CLASSIFICATION:	AIR TRANSPORTATION, SCHEDULED [4512]
		IRS NUMBER:				741563240
		STATE OF INCORPORATION:			TX
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2702 LOVE FIELD DR
		STREET 2:		P O BOX 36611
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75235
		BUSINESS PHONE:		2147924000

	MAIL ADDRESS:	
		STREET 1:		PO BOX 36611
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75235-1611

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	AIR SOUTHWEST CO
		DATE OF NAME CHANGE:	19760108

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BIEGLER DAVID W
		CENTRAL INDEX KEY:			0001222590

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-07259
		FILM NUMBER:		07864696

	MAIL ADDRESS:	
		STREET 1:		TRINITY INDUSTRIES INC
		STREET 2:		2525 STEMMONS FREEWAY
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75207
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-05-16</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000092380</issuerCik>
        <issuerName>SOUTHWEST AIRLINES CO</issuerName>
        <issuerTradingSymbol>LUV</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001222590</rptOwnerCik>
            <rptOwnerName>BIEGLER DAVID W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SOUTHWEST AIRLINES CO.</rptOwnerStreet1>
            <rptOwnerStreet2>P.O. BOX 36611</rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75235-1611</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-05-16</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>14.42</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-05-16</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>8000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2017-05-16</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>8000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each share of phantom stock is the economic equivalent of one share of Southwest's Common Stock, and may be settled only in cash.</footnote>
        <footnote id="F2">Phantom shares settle on the 30th calendar day following the date on which the Reporting Person ceases to serve as a Director of the Issuer.</footnote>
        <footnote id="F3">The option vests annually with respect to one-third of the shares covered thereby, beginning on May 16, 2008.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>On behalf of and attorney-in-fact for David W. Biegler /s/ Deborah Ackerman</signatureName>
        <signatureDate>2007-05-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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