Exhibit 5.1

September 9, 2020

Starboard Value Acquisition Corp.

777 Third Avenue, 18^th Floor

New York, NY 10017

Ladies and Gentlemen:

We have acted as special counsel to Starboard Value Acquisition Corp., a Delaware corporation (the “Company”), in connection with (i) the preparation and filing by the Company with the Securities and Exchange Commission (the “SEC”) of a Registration Statement on Form S-1 (the “462(b) Registration Statement”), under the Securities Act of 1933, as amended (the “Act”), relating to an underwritten public offering (the “Offering”) by the Company of up to 6,900,000 units of the Company (including up to 900,000 units subject to the Underwriters’ (as defined below) overallotment option) (the “Units”), each Unit consisting of one share of the Company’s Class A common stock, par value $0.0001 per share (the “Class A Shares”), and one-sixth of one redeemable warrant (the “Detachable Redeemable Warrants”) and (ii) the Company’s proposed Amended and Restated Certificate of Incorporation (the “Certificate of Incorporation”), which provides that up to an aggregate number of redeemable warrants equal to the number of Units issued in the Company’s initial public offering (of which the Offering is a part) multiplied by one-sixth, of which 1,150,000 warrants are registered on the 462(b) Registration Statement (the “Distributable Redeemable Warrants”, and together with the Detachable Redeemable Warrants, the “Warrants”) will be distributed on a pro rata basis only to holders of Class A Shares issued in the Company’s initial public offering (whether acquired by any such holder in the initial public offering or afterwards) that are outstanding after the time at which the Company redeems any Class A Shares that the holders thereof have elected to redeem in connection with the Company’s initial business combination, all as more fully described in the prospectus included in the Registration Statement on Form S-1, as amended (File No. 333-248094), filed by the Company with the SEC (the “Registration Statement”). This opinion is being furnished in accordance with the requirements of Item 601(b)(5) of Regulation S-K under the Act.

We have examined originals or certified copies of (i) such corporate records of the Company and other certificates and documents of officials of the Company, public officials and others as we have deemed appropriate for purposes of this letter, (ii) the 462(b) Registration Statement, (iii) the Registration Statement (the “Registration Statement”), (iv) the form of Bylaws of the Company, filed as Exhibit 3.3 to the Registration Statement, (v) the form of Certificate of Incorporation, filed as Exhibit 3.2 to the Registration Statement, (vi) the form of Underwriting Agreement to be entered into between the Company and UBS Securities LLC, as representative of the underwriters named therein (the “Underwriting Agreement”), filed as Exhibit 1.1 to the Registration Statement, (vii) the form of Warrant Agreement to be entered into between the Company and Continental Stock Transfer & Trust Company, as warrant agent (the “Warrant Agreement”), filed as Exhibit 4.4 to the Registration Statement, (viii) the specimen Unit certificate, filed as exhibit 4.1 to the Registration Statement, (ix) the specimen Class A common stock certificate, filed as exhibit 4.2 to the Registration Statement, and (x) the specimen Warrant certificate, filed as Exhibit 4.3 to the Registration Statement. We have assumed the genuineness of all signatures, the legal capacity of all natural persons, the authenticity of all documents submitted to us as originals, and the conformity to authentic original documents of all copies submitted to us as conformed, certified or reproduced copies. We have also assumed that, at the time of execution, countersignature, issuance and delivery of any Warrants, the Warrant Agreement, in substantially the form filed as an exhibit to the Registration Statement, will be the valid and binding obligation of the warrant agent, enforceable against the warrant agent in accordance with its terms. As to various questions of fact relevant to this letter, we have relied, without independent investigation, upon certificates of public officials and certificates of officers of the Company, all of which we assume to be true, correct and complete.

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Based upon the foregoing, and subject to the assumptions, exceptions, qualifications and limitations stated herein, we are of the opinion that:

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The opinions and other matters in this letter are qualified in their entirety and subject to the following:

We hereby consent to the filing of this opinion as an exhibit to the 462(b) Registration Statement and to the use of our name in the Prospectus forming a part of the Registration Statement under the caption “Legal matters.” In giving this consent, we do not thereby admit that we are within the category of persons whose consent is required under Section 7 of the Act and the rules and regulations thereunder.