<SEC-DOCUMENT>0001235802-21-000136.txt : 20211124
<SEC-HEADER>0001235802-21-000136.hdr.sgml : 20211124
<ACCEPTANCE-DATETIME>20211124162835
ACCESSION NUMBER:		0001235802-21-000136
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20211123
FILED AS OF DATE:		20211124
DATE AS OF CHANGE:		20211124

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MARTEN RANDOLPH L
		CENTRAL INDEX KEY:			0001253979

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-15010
		FILM NUMBER:		211447213

	MAIL ADDRESS:	
		STREET 1:		129 MARTEN STREET
		CITY:			MONDOVI
		STATE:			WI
		ZIP:			54755

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MARTEN TRANSPORT LTD
		CENTRAL INDEX KEY:			0000799167
		STANDARD INDUSTRIAL CLASSIFICATION:	TRUCKING (NO LOCAL) [4213]
		IRS NUMBER:				391140809
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		129 MARTEN ST
		CITY:			MONDOVI
		STATE:			WI
		ZIP:			54755
		BUSINESS PHONE:		7159264216

	MAIL ADDRESS:	
		STREET 1:		3400 PLAZA VII
		STREET 2:		45 SOUTH SEVENTH ST
		CITY:			MINNEAPOLIS
		STATE:			MN
		ZIP:			55402
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-11-23</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000799167</issuerCik>
        <issuerName>MARTEN TRANSPORT LTD</issuerName>
        <issuerTradingSymbol>MRTN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001253979</rptOwnerCik>
            <rptOwnerName>MARTEN RANDOLPH L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>129 MARTEN STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MONDOVI</rptOwnerCity>
            <rptOwnerState>WI</rptOwnerState>
            <rptOwnerZipCode>54755</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Exec. Chairman of the Board</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-11-23</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>14807</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>17.37</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17711382.37</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These shares were withheld to cover the estimated tax withholding obligations in connection with the issuance of 40,018 shares released from the Issuer's deferred compensation plan which terminated effective May 5, 2021.</footnote>
        <footnote id="F2">Includes: (i) 11,999 shares granted under a Performance Unit Award Agreement that vest on 12/31/2021 through 12/31/2025; (ii) 4,256 shares granted under a Performance Unit Award Agreement that vest on 12/31/2021 through 12/31/2024; (iii) 6,840 shares granted under a Performance Unit Award Agreement that vest on 12/31/2021 through 12/31/2023; (iv) 4,350 shares granted under a Performance Unit Award Agreement that vest on 12/31/2021 through 12/31/2022; (v) 5,200 shares granted under a Performance Unit Award Agreement that vest on 12/31/2021; and (vi) 40,017.37 shares that the reporting person has deferred under the Issuer's deferred compensation plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ James J. Hinnendael, attorney-in-fact</signatureName>
        <signatureDate>2021-11-23</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
