<SEC-DOCUMENT>0001020569-23-000193.txt : 20231006
<SEC-HEADER>0001020569-23-000193.hdr.sgml : 20231006
<ACCEPTANCE-DATETIME>20231006161043
ACCESSION NUMBER:		0001020569-23-000193
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20231005
FILED AS OF DATE:		20231006
DATE AS OF CHANGE:		20231006

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MARSON DEBORAH
		CENTRAL INDEX KEY:			0001691591

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13045
		FILM NUMBER:		231314334

	MAIL ADDRESS:	
		STREET 1:		C/O IRON MOUNTAIN INCORPORATED
		STREET 2:		ONE FEDERAL STREET
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02110

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			IRON MOUNTAIN INC
		CENTRAL INDEX KEY:			0001020569
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		IRS NUMBER:				232588479
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		85 NEW HAMPSHIRE AVENUE, SUITE 150
		STREET 2:		PEASE INTERNATIONAL TRADEPORT
		CITY:			PORTSMOUTH
		STATE:			NH
		ZIP:			03801
		BUSINESS PHONE:		617-535-4781

	MAIL ADDRESS:	
		STREET 1:		1101 ENTERPRISE DRIVE
		CITY:			ROYERSFORD
		STATE:			PA
		ZIP:			19468

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	IRON MOUNTAIN INC/PA
		DATE OF NAME CHANGE:	20000201

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	PIERCE LEAHY CORP
		DATE OF NAME CHANGE:	19960807
</SEC-HEADER>
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<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_169662302974260.xml
<DESCRIPTION>FORM 4
<TEXT>
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<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2023-10-05</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001020569</issuerCik>
        <issuerName>IRON MOUNTAIN INC</issuerName>
        <issuerTradingSymbol>IRM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001691591</rptOwnerCik>
            <rptOwnerName>MARSON DEBORAH</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O IRON MOUNTAIN INCORPORATED</rptOwnerStreet1>
            <rptOwnerStreet2>85 NEW HAMPSHIRE AVENUE, SUITE 150</rptOwnerStreet2>
            <rptOwnerCity>PORTSMOUTH</rptOwnerCity>
            <rptOwnerState>NH</rptOwnerState>
            <rptOwnerZipCode>03801</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP, General Counsel, Sec.</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>1</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $.01 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2023-10-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>57.68</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>56026</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes></footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Keely Stewart, under Power of Attorney dated April 17, 2023, from Deborah Marson</signatureName>
        <signatureDate>2023-10-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24
<SEQUENCE>2
<FILENAME>ex-24.htm
<DESCRIPTION>MARSON POA 4-17-2023
<TEXT>
<!-- Document created using Workiva -->
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<pre>
POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS, that I, Deborah Marson, do hereby make, constitute and appoint, Keely Stewart, Assistant Secretary of Iron Mountain Incorporated and Luke Cummiskey, Manager, Senior Corporate Counsel, acting singly, to be my lawful attorney-in-fact for me and to do any and all acts which I could do in connection with any filings required by Section 16 of the Securities Exchange Act of 1934, including, without limitation, the preparation, signing and filing of Forms 3, 4 and 5 ("Section 16 Filings").

Among the powers granted to my attorney-in-fact are:

To prepare, sign and file with the Securities and Exchange Commission and the New York Stock Exchange the Section 16 Filings, in my name or stead, and any and all such further documents as he/she may deem necessary or advisable in order to carry out the required Section 16 Filings and the powers granted to him/her by these presents.

This Power of Attorney shall remain in effect until revoked by the undersigned in writing.

IN WITNESS WHEREOF, I have hereunto set my hand and seal this 17 day of April, 2023.

__/s/ Deborah Marson______
Name: Deborah Marson
</pre>
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</SEC-DOCUMENT>
