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Exhibit 5.1

September 26, 2022

GreenLight Biosciences Holdings, PBC

200 Boston Avenue

Suite 3100

Medford, MA 02155

Re:    Registration Statement on Form S-1

Ladies and Gentlemen:

We are acting as counsel to GreenLight Biosciences Holdings, PBC, a Delaware corporation (the “Company”), in connection with its filing on the date hereof with the Securities and Exchange Commission (the “Commission”) of a registration statement on Form S-1 (the “Registration Statement”) under the Securities Act of 1933, as amended (the “Securities Act”), relating to the registration of, among other things, the resale from time to time by the selling securityholders named in the Registration Statement of up to 420,000 shares (the “Option Shares”) of the Company’s common stock, par value $0.0001 per share (the “Common Stock”), issuable upon exercise of outstanding options (the “Options”).

We have examined the Certificate of Incorporation and Bylaws of the Company, each as restated or amended to date, records of meetings and consents of the Board of Directors, or committees thereof, and records of the proceedings of stockholders deemed to be relevant to this opinion letter, each as provided to us by the Company, and the Registration Statement. We have also reviewed such other documents which we consider necessary or advisable for the purposes of rendering the opinions set forth below, including the Company’s 2022 Equity and Incentive Plan (the “Plan”), filed as Exhibit 10.5 to the Registration Statement, pursuant to which the Options were issued.

We have examined such matters of fact and questions of law as we have considered appropriate for the purposes of this letter. We have relied upon certificates and other assurances of officers of the Company and others as to factual matters without having independently verified such factual matters. In our examination, we have assumed the genuineness of all signatures, the authenticity of all documents submitted to us as originals, the conformity to authentic original documents of all documents submitted to us as copies 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 of such documents.

GreenLight Biosciences Holdings, PBC

September 26, 2022

Page 2

We have assumed that the Company will continue to have sufficient authorized, unissued and otherwise unreserved shares of Common Stock available for issuance at the time of each issuance of Option Shares upon exercise of the Options. Further, we have assumed that the applicable exercise price of each Option will not be adjusted to an amount below the par value per share of the Common Stock.

The opinion expressed below is limited to the General Corporation Law of the State of Delaware.

On the basis of the foregoing, it is our opinion that, as of the date hereof, the Option Shares, when issued and paid for in accordance with the terms of the Plan and the Options, will be validly issued, fully paid and non-assessable.

This opinion is being delivered solely for the benefit of the Company and such other persons as are entitled to rely upon it pursuant to the applicable provisions of the Securities Act. This opinion may not be used, quoted, relied upon or referred to for any other purpose, nor may this opinion be used, quoted, relied upon or referred to by any other person, for any purpose, without our prior written consent.

This opinion is based upon currently existing statutes, rules and regulations and judicial decisions and is rendered as of the date hereof, and we disclaim any obligation to advise you of any change in any of the foregoing sources of law or subsequent developments in law or changes in facts or circumstances which might affect any matters or opinions set forth herein.

This opinion letter shall be interpreted in accordance with the Core Opinion Principles jointly issued by the Committee on Legal Opinions of the American Bar Association’s Business Law Section and the Working Group on Legal Opinions Foundation as published in 74 Business Lawyer 815 (2019).

We consent to your filing this opinion as an exhibit to the Registration Statement and to the reference to our firm in the prospectus constituting part of the Registration Statement under the heading “Legal Matters.” 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 or the rules and regulations of the Commission thereunder.

Very truly yours,
FOLEY HOAG LLP
By:	/s/ John D. Hancock
	a Partner