-----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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<SEC-DOCUMENT>0001140361-10-002443.txt : 20100122
<SEC-HEADER>0001140361-10-002443.hdr.sgml : 20100122
<ACCEPTANCE-DATETIME>20100122155905
ACCESSION NUMBER:		0001140361-10-002443
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100121
FILED AS OF DATE:		20100122
DATE AS OF CHANGE:		20100122

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Bishkin S. James
		CENTRAL INDEX KEY:			0001441446

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34143
		FILM NUMBER:		10542106

	MAIL ADDRESS:	
		STREET 1:		1920 NACOGDOCHES ROAD
		STREET 2:		SUITE 201
		CITY:			SAN ANTONIO
		STATE:			TX
		ZIP:			78209

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			RACKSPACE HOSTING, INC.
		CENTRAL INDEX KEY:			0001107694
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-COMPUTER PROGRAMMING, DATA PROCESSING, ETC. [7370]
		IRS NUMBER:				743016523
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		5000 WALZEM RD.
		CITY:			SAN ANTONIO
		STATE:			TX
		ZIP:			78218
		BUSINESS PHONE:		2103124000

	MAIL ADDRESS:	
		STREET 1:		5000 WALZEM RD.
		CITY:			SAN ANTONIO
		STATE:			TX
		ZIP:			78218

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	RACKSPACE INC
		DATE OF NAME CHANGE:	20080403

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	RACKSPACE MANAGED HOSTING INC
		DATE OF NAME CHANGE:	20000725

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	RACKSPACE COM INC
		DATE OF NAME CHANGE:	20000224
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-01-21</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001107694</issuerCik>
        <issuerName>RACKSPACE HOSTING, INC.</issuerName>
        <issuerTradingSymbol>RAX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001441446</rptOwnerCik>
            <rptOwnerName>Bishkin S. James</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O RACKSPACE HOSTING, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>5000 WALZEM RD.</rptOwnerStreet2>
            <rptOwnerCity>SAN ANTONIO</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>78218</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-01-21</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>22.2536</value>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>339489</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-01-21</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                    <footnoteId id="F5"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>22.2536</value>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>28616</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Shares held by Bishkin 2000 Family, LP.</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Mr. Bishkin is the general partner of the Bishkin 2000 Family, LP. Mr. Bishkin dislaims beneficial ownership of shares held by Bishkin 2000 Family, LP, except to the extent of any pecuniary interest therein.</footnote>
        <footnote id="F2">These shares were sold pursuant to Mr. Bishkin's Rule 10b5-1 trading plan adopted by Mr. Bishkin on August 26, 2008.</footnote>
        <footnote id="F3">The prices for these sales of shares ranged from $21.76 to $22.88 per share.</footnote>
        <footnote id="F4">The registrant undertakes to provide, upon request by the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares purchased or sold at each separate price.</footnote>
        <footnote id="F5">These shares were sold pursuant to instructions given by the Bishkin 2000 Family LP through its general partner pursuant to a Rule 10b5-1 trading plan adopted by the partnership on August 26, 2008.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>William Alberts by Power of Attorney</signatureName>
        <signatureDate>2010-01-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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