Exhibit 5.3

May 11, 2021

Extra Space Storage Inc.

2795 East Cottonwood Parkway

Suite 300

Salt Lake City, UT 84121

Ladies and Gentlemen:

We have acted as special Massachusetts counsel to ESS Holdings Business Trust I, a Massachusetts business trust (“ESS I”), and ESS Holdings Business Trust II, a Massachusetts business trust (“ESS II”) (each, a “Trust” and collectively, the “Trusts”), in connection with the issuance and sale by Extra Space Storage LP, a Delaware limited partnership (the “Operating Partnership”), of $450,000,000 aggregate principal amount of 2.550% Senior Notes due 2031 (the “Notes”) and the guarantee of the Notes by the Trusts and Extra Space Storage Inc., a Maryland corporation (together with the Trusts, “Guarantors”), of the obligations of the Operating Partnership under the Notes, each covered by the above-referenced Registration Statement, and all amendments thereto (collectively, the “Registration Statement”), filed by the Operating Partnership and Guarantors with the United States Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “1933 Act”). The Notes and the Guarantee are being issued pursuant to an indenture dated as of the date hereof among the Operating Partnership, Guarantors and Wells Fargo Bank, National Association, as trustee (the “Trustee”), as supplemented by the First Supplemental Indenture, dated as of the date hereof, among the Operating Partnership, Guarantors and the Trustee (collectively, the “Indenture”).

In such capacity, we have examined the following documents (the “Documents”):

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In such examination, we have assumed (i) the genuineness of all signatures, including the compliance of all electronic signatures with all laws relating thereto, (ii) the authenticity of all documents, agreements and instruments submitted to us as originals, (iii) the conformity to original documents, agreements and instruments of all documents, agreements, and instruments submitted to us as copies or specimens, (iv) the authenticity of the originals of such documents, agreements and instruments submitted to us as copies or specimens, (v) the accuracy of the matters set forth in the documents, agreements and instruments we reviewed, (vi) the accuracy and valid issuance of all public documents, and (vii) the legal capacity and competency of each natural person executing any of the Documents. In reaching the opinions set forth below, we have further assumed that each Trust has received an economic benefit that is fair and sufficient to support its execution and delivery of the Indenture (including the Guarantee contained therein). In addition, we call your attention to the fact that we do not represent the Trusts generally. Accordingly, in rendering the opinions set forth herein we have relied exclusively on the Documents.

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Based on the foregoing and subject to the assumptions and qualifications set forth in this letter, it is our opinion that:

In addition to the assumptions and qualifications set forth above, the opinions set forth above are subject to following qualifications:

This opinion is provided to you as a legal opinion only and not as a guaranty or warranty of the matters discussed herein. This opinion is being furnished to you for submission to the Commission as an exhibit to the Registration Statement. Latham & Watkins LLP, counsel to the Operating Partnership, may rely on this opinion in connection with its opinion of even date herewith relating to the Notes. We hereby consent to the filing of this opinion as an exhibit to the

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Registration Statement and to the use of the name of our firm therein. In giving this consent, we do not admit that we are within the category of persons whose consent is required by Section 7 of the 1933 Act.