-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 VB0Hz+Vh2XxkRgzqdLUOC0WERXXWgpA72HbFsHMfrs/zmjcR4Iano6STJcPku7Fb
 VGRcOaoLyT2Za+0CHHklHA==

<SEC-DOCUMENT>0001027713-06-000002.txt : 20060427
<SEC-HEADER>0001027713-06-000002.hdr.sgml : 20060427
<ACCEPTANCE-DATETIME>20060427164515
ACCESSION NUMBER:		0001027713-06-000002
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20060426
FILED AS OF DATE:		20060427
DATE AS OF CHANGE:		20060427

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:			MONTFORD JOHN T
		CENTRAL INDEX KEY:			0001189134

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-07259
		FILM NUMBER:		06785841

	BUSINESS ADDRESS:	
		STREET 1:		C/O SOUTHWEST AIRLINES CO
		STREET 2:		2702 FIELD DR PO BOX 36611
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75235-1611
		BUSINESS PHONE:		2147924000

	MAIL ADDRESS:	
		STREET 1:		C/O SOUTHWEST AIRLINES CO
		STREET 2:		2702 LOVE FIELD DR PO BOX 36611
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75235-1611
</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>2006-04-26</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001189134</rptOwnerCik>
            <rptOwnerName>MONTFORD JOHN T</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SOUTHWEST AIRLINES CO</rptOwnerStreet1>
            <rptOwnerStreet2>2702 LOVE FIELD DR PO 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>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2006-04-26</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1150</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>16.28</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2700</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>On behalf of and attorney in fact for John T. Montford /s/ Deborah Ackerman</signatureName>
        <signatureDate>2006-04-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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