Exhibit 5.1

2100 L Street, NW Suite 900 Washington, D.C. 20037 Telephone: 202.887.1500 Facsimile: 202.887.0763 www.mofo.com

morrison & foerster llp Austin, beijing, berlin, boston, brussels, denver, hong kong, london, los angeles, new york, palo alto, san diego, san francisco, shanghai, singapore, tokyo, washington, d.c.

October 25, 2022

Board of Directors

Greenlane Holdings, Inc.
1095 Broken Sound Parkway, Suite 300

Boca Raton, Florida 33487

Re: Greenlane Holdings, Inc. - Proposed Sale of Class A Common Stock and Warrants to Purchase Shares of Class A Common Stock under Registration Statement on Form S-1 (File No. 333-267782)

Ladies and Gentlemen:

We have acted as counsel to Greenlane Holdings, Inc., a Delaware corporation (the “Company”), in connection with its registration statement on Form S-1, as amended (the “Registration Statement”), filed with the Securities and Exchange Commission under the Securities Act of 1933, as amended (the “Securities Act”), relating to the registration under the Securities Act of the issuance of up to 4,878,048 units (“Units”), each consisting of (x) one share (each a “Share” and, collectively, the “Shares”) of the Company’s Class A common stock, par value $0.01 per share (the “Class A common stock”) or one pre-funded warrant (each a “Pre-Funded Warrant” and, collectively, the “Pre-Funded Warrants”) and (y) two warrants to purchase one share of Class A common stock (each a “Standard Warrant” and collectively, the “Standard Warrants” and, together with the Pre-Funded Warrants, the “Warrants”), as specified in the Registration Statement (File No. 333-267782). The Shares are to be sold by the Company pursuant to the proposed form of Placement Agency Agreement by and between the Company and A.G.P./Alliance Global Partners filed as Exhibit 1.1 to the Registration Statement (the “Placement Agency Agreement”) and the proposed form of Securities Purchase Agreement by and between the Company and the purchasers named therein filed as Exhibit 10.25 to the Registration Statement (the “Securities Purchase Agreement”). The Shares, the Warrants and the shares of Class A common stock issuable upon exercise of the Warrants (the “Warrant Shares”) are sometimes referred to collectively herein as the “Securities.”

As counsel for the Company, we have examined the Placement Agency Agreement, the Securities Purchase Agreement, the Registration Statement, the Company’s Amended and Restated Certificate of Incorporation (the “Charter”) and the Company’s bylaws, as well as originals or copies, certified or otherwise identified to our satisfaction, of such other documents, corporate records, certificates of public officials and other instruments as we have deemed necessary for the purposes of rendering this opinion and we are familiar with the proceedings taken and proposed to be taken by the Company in connection with the authorization, issuance and sale of the Shares. In our examination, we have assumed the genuineness of all signatures, the authenticity of all documents submitted to us as originals and the conformity with the originals of all documents submitted to us as copies. We have further assumed that, upon the issuance of any of the Securities, the total number of shares of Class A common stock issued and outstanding will not exceed the total number of shares of Class A common stock that the Company is then authorized to issue under the Charter. This opinion letter is given, and all statements herein are made, in the context of the foregoing.

Board of Directors

Greenlane Holdings, Inc.

October 25, 2022

Page Two

This opinion letter is based as to matters of law solely on the Delaware General Corporation Law, as amended. We express no opinion herein as to any other laws, statutes, ordinances, rules, or regulations. As used herein, the term “Delaware General Corporation Law, as amended” includes the statutory provisions contained therein, all applicable provisions of the Delaware Constitution and reported judicial decisions interpreting these laws.

Based upon, subject to and limited by the foregoing, it is our opinion that:

(i) upon issuance, delivery and payment therefor in the manner contemplated by the Registration Statement, the Securities Purchase Agreement, and resolutions of the Board of Directors or a duly authorized committee thereof, the Units will constitute legal, valid and binding obligations of the Company;

(ii) upon issuance, delivery and payment therefor in the manner contemplated by the Registration Statement, the Securities Purchase Agreement, and resolutions of the Board of Directors or a duly authorized committee thereof, the Shares will be validly issued, fully paid and nonassessable;

(iii) upon exercise of the Warrants and the issuance, delivery and payment for the Warrant Shares in the manner contemplated by the Warrants, the Warrant Shares will be validly issued, fully paid and nonassessable; and

(iv) the Warrants included in the Units, when the Units are duly issued, delivered and paid for as contemplated in the Registration Statement and in accordance with their terms and the terms of the Securities Purchase Agreement, will constitute legal, valid and binding obligations of the Company.

Our opinions expressed herein are subject to the following qualifications and exceptions:

Board of Directors

Greenlane Holdings, Inc.

October 25, 2022

Page Three

This opinion is furnished to you in connection with the Registration Statement. No opinion may be implied or inferred beyond the opinion expressly stated. This opinion is given as of the date hereof, and we assume no obligation to advise you of any changes in applicable law or any facts or circumstances that come to our attention after the date hereof that may affect the opinion contained herein.

We hereby consent to the filing of this opinion as Exhibit 5.1 to the Registration Statement and to the reference to our firm contained under the heading “Legal Matters” in the Registration Statement. In giving this consent, we do not admit that we are in the category of persons whose consent is required by Section 7 of the Securities Act or the rules and regulations promulgated by the Commission.