EX-5.1

Exhibit 5.1

LOGO

Bradley M. Libuit

+1 415 693 2021

blibuit@cooley.com

July 2, 2020

Cornerstone OnDemand, Inc.

1601 Cloverfield Blvd.

Suite 620 South

1241Santa Monica, CA 90404

Ladies and Gentlemen:

You have requested our opinion, as counsel to Cornerstone OnDemand, Inc., a Delaware corporation (the “Company”), with respect to certain matters in connection with the filing by the Company of a Registration Statement on Form S-3 (the “Registration Statement”) with the Securities and Exchange Commission, including a related prospectus (the “Prospectus”), covering the registration for resale of 1,110,352 shares of common stock, $0.0001 par value, of the Company (the “Shares”). We have been advised that the Shares were issued by the Company pursuant to that certain Purchase Agreement, dated as of February 24, 2020, by and among the Company, 1241593 B.C. Ltd., Cornerstone OnDemand UK Holdings Limited, and Vector Talent Holdings, L.P., as amended by that certain Amendment Agreement, dated as of April 22, 2020 (together, the “Purchase Agreement”).

In connection with this opinion, we have examined and relied upon the Registration Statement, the Prospectus, the Company’s Amended and Restated Certificate of Incorporation, as amended, the Company’s Amended and Restated Bylaws, the Purchase Agreement and originals or copies certified to our satisfaction of such records, documents, certificates, memoranda and other instruments as in our judgment are necessary or appropriate to enable us to render the opinion expressed below. We have assumed the genuineness and authenticity of all documents submitted to us as originals and the conformity to originals of all documents submitted to us as copies thereof; the accuracy, completeness and authenticity of certificates of public officials; and the due execution and delivery of all documents by all persons other than the Company where due execution and delivery are prerequisites to the effectiveness thereof. As to certain factual matters, we have relied upon a certificate of an officer of the Company and have not independently verified such matters.

Our opinion is expressed only with respect to the General Corporation Law of the State of Delaware. We express no opinion to the extent that any other laws are applicable to the subject matter hereof and express no opinion and provide no assurance as to compliance with any federal or state securities law, rule or regulation.

On the basis of the foregoing, and in reliance thereon, we are of the opinion that the Shares have been validly issued and are fully paid and non-assessable.

Cooley LLP 101 California Street 5th Floor San Francisco, CA 94111-5800

t: (415) 693-2000 f: (415) 693-2222 cooley.com