Exhibit 5.1

HOWARD & HOWARD ATTORNEYS PLLC

June 30, 2021

Alta Equipment Group Inc.

13211 Merriman Road

Livonia, Michigan 48150

Re: Post-Effective Amendment No. 1 to Form S-1 on Form S-3 Registration Statement

Ladies and Gentlemen:

We have acted as special counsel to Alta Equipment Group Inc., a Delaware corporation (the “Company”), in connection with the preparation of the Company’s post-effective amendment No. 1 to Form S-1 on Form S-3 registration statement to be filed with the U.S. Securities and Exchange Commission (the “Commission”) on or about the date hereof (the “Registration Statement”), under the Securities Act of 1933, as amended (the “Securities Act”).

The Registration Statement relates to the resale or distribution from time to time by the selling securityholders named in the prospectus contained in the Registration Statement and any supplement thereto or their permitted transferees of up to 17,666,645 shares of Common Stock (the “Selling Securityholder Shares”).

This opinion letter is being furnished in accordance with the requirements of Item 601(b)(5) of Regulation S-K promulgated under the Securities Act.

In rendering the opinions set forth below, we have examined and relied upon such certificates, corporate records, agreements, instruments and other documents, and examined such matters of law, that we considered necessary or appropriate as a basis for the opinions. We have examined and are familiar with originals or copies, certified or otherwise identified to our satisfaction, of (i) the third amended and restated certificate of incorporation of the Company, as in effect on the date hereof, (ii) the Registration Statemen and all post-effective amendments thereto, and (iii) such other documents as we have deemed necessary or appropriate as a basis for the opinions set forth below. In our examination, we have assumed the legal capacity of all natural persons, the genuineness of all signatures, the authenticity of all documents submitted to us as originals, the conformity to original documents of all documents submitted to us as certified or photostatic copies, the authenticity of the originals of such latter documents, that all parties to such documents (other than the Company) had the power, corporate or other, to enter into and perform all obligations thereunder, that all such documents have been duly authorized by all requisite action, corporate or other, and duly executed and delivered by all parties thereto (other than the Company) and that all such documents constitute the valid and binding obligation of each party thereto (other than the Company) enforceable against each such party in accordance with their terms. As to any facts material to the opinions expressed herein that we did not independently establish or verify, we have relied upon oral or written statements and representations of officers and other representatives of the Company and others.

Based upon the foregoing and subject to the assumptions, qualifications and limitations set forth herein, we are of the opinion that the Selling Securityholder Shares have been duly authorized and are validly issued, fully paid and non-assessable.

The opinions expressed herein are based upon and limited to the General Corporation Law of the State of Delaware (including the statutory provisions, the applicable provisions of the Delaware Constitution and reported judicial decisions interpreting the foregoing) and the laws of the State of Michigan. We express no opinion herein as to any other laws, statutes, regulations or ordinances. The opinions expressed herein that are based on the laws of the

State of Michigan are limited to the laws generally applicable in transactions of the type covered by the Registration Statement.

We hereby consent to the filing of this opinion letter as Exhibit 5.1 to the Registration Statement and to the reference to our firm under the caption “Legal Matters” in the prospectus included in the Registration Statement. In giving such consent, we do not thereby admit that we are experts within the meaning of the Securities Act or the rules and regulations of the Commission or that this consent is required by Section 7 of the Securities Act.

Very truly yours,

/s/ Howard & Howard Attorneys PLLC