<SEC-DOCUMENT>0001127602-21-006802.txt : 20210219
<SEC-HEADER>0001127602-21-006802.hdr.sgml : 20210219
<ACCEPTANCE-DATETIME>20210219165435
ACCESSION NUMBER:		0001127602-21-006802
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210217
FILED AS OF DATE:		20210219
DATE AS OF CHANGE:		20210219

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Nickolas James AJ
		CENTRAL INDEX KEY:			0001715189

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-12744
		FILM NUMBER:		21656759

	MAIL ADDRESS:	
		STREET 1:		2710 WYCLIFF ROAD
		CITY:			RALEIGH
		STATE:			NC
		ZIP:			27607

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MARTIN MARIETTA MATERIALS INC
		CENTRAL INDEX KEY:			0000916076
		STANDARD INDUSTRIAL CLASSIFICATION:	MINING, QUARRYING OF NONMETALLIC MINERALS (NO FUELS) [1400]
		IRS NUMBER:				561848578
		STATE OF INCORPORATION:			NC
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2710 WYCLIFF ROAD
		CITY:			RALEIGH
		STATE:			NC
		ZIP:			27607
		BUSINESS PHONE:		919-781-4550

	MAIL ADDRESS:	
		STREET 1:		2710 WYCLIFF ROAD
		CITY:			RALEIGH
		STATE:			NC
		ZIP:			27607
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
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<DESCRIPTION>PRIMARY DOCUMENT
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    <periodOfReport>2021-02-17</periodOfReport>

    <issuer>
        <issuerCik>0000916076</issuerCik>
        <issuerName>MARTIN MARIETTA MATERIALS INC</issuerName>
        <issuerTradingSymbol>MLM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001715189</rptOwnerCik>
            <rptOwnerName>Nickolas James AJ</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>MARTIN MARIETTA MATERIALS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>2710 WYCLIFF ROAD</rptOwnerStreet2>
            <rptOwnerCity>RALEIGH</rptOwnerCity>
            <rptOwnerState>NC</rptOwnerState>
            <rptOwnerZipCode>27607</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
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        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>SVP and CFO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-02-17</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3928</value>
                    <footnoteId id="F1"/>
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                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
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                    <value>15929</value>
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                    <value>D</value>
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                    <value>1766</value>
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                <transactionPricePerShare>
                    <value>325.30</value>
                </transactionPricePerShare>
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                    <value>D</value>
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            <securityTitle>
                <value>Common Stock</value>
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                <transactionPricePerShare>
                    <value>260.24</value>
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                <sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-02-17</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1526</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
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    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents the settlement of performance share units into common stock that were granted under the Martin Marietta Amended and Restated Stock Based Award Plan on February 22, 2018. The ultimate amount of shares to be received under the grant depended on the achievement of performance goals during a three-year performance period from January 1, 2018 through December 31, 2020. On February 17, 2021, Martin Marietta's Management Development and Compensation Committee certified the attainment of the applicable performance goals and approved the settlement of the PSU grant. The shares underlying the PSUs vested on December 31, 2020.</footnote>
        <footnote id="F2">Restricted stock unit award granted under the Martin Marietta Materials, Inc. Amended and Restated Stock-Based Award Plan, which award vests pro rata in equal installments over three years from the date of grant.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Roselyn R. Bar, attorney-in-fact</signatureName>
        <signatureDate>2021-02-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
