Exhibit 5.1

Jon C. Avina

T: +1 650 843 5307

javina@cooley.com

April 25, 2024

Rubrik, Inc.

3495 Deer Creek Road,

Palo Alto, CA 94304

Ladies and Gentlemen:

We have acted as counsel to Rubrik, Inc., a Delaware corporation (the “Company”), in connection with the filing by the Company of a Registration Statement on Form S-8 (the “Registration Statement”) with the Securities and Exchange Commission (the “Commission”) covering the registration for resale of up to 2,326,888 shares (the “Shares”) of the Company’s Class A Common Stock, $0.000025 par value, on behalf of the selling stockholders described in the prospectus (the “Prospectus”) included in the Registration Statement.

In connection with this opinion, we have examined and relied upon (a) the Registration Statement and the Prospectus, (b) the Company’s certificate of incorporation and bylaws, each as currently in effect, (c) the employee benefit plan pursuant to which the Shares were or may be issued, and (d) such other records, documents, opinions, certificates, memoranda and instruments as in our judgment are necessary or appropriate to enable us to render the opinion expressed below. We have assumed the genuineness of all signatures, the authenticity of all documents submitted to us as originals, the conformity to originals of all documents submitted to us as copies, the accuracy, completeness and authenticity of certificates of public officials and the due authorization, execution and delivery of all documents by all persons other than the Company where authorization, 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 are validly issued, fully paid and nonassessable, except with respect to Shares to be acquired upon the settlement of restricted stock units issued by the Company or the conversion of the Company’s Class B Common Stock, $0.000025 par value, which Shares will be validly issued, fully paid and nonassessable upon such settlement or conversion.

This opinion is limited to the matters expressly set forth in this letter, and no opinion has been or should be implied, or may be inferred, beyond the matters expressly stated. This opinion speaks only as to law and facts in effect or existing as of the date hereof and we have no obligation or responsibility to update or supplement this opinion to reflect any facts or circumstances that may hereafter come to our attention or any changes in law that may hereafter occur.

Rubrik, Inc.

April 25, 2024

Page Two

We consent to the filing of this opinion as an exhibit to the Registration Statement and to the reference to our firm under the heading “Legal Matters” in the Prospectus. In giving such consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act of 1933, as amended, or the rules and regulations of the Commission thereunder.

Sincerely,
COOLEY LLP
By:	/s/ Jon C. Avina
	Jon C. Avina

Cooley LLP 3175 Hanover Street Palo Alto, CA 94304-1130

t: +1 650 843 5000 f: +1 650 843 7400 cooley.com