EX-5.1

Exhibit 5.1

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263 Tresser Boulevard | Suite 1400 | Stamford, CT 06901| P.O. Box 1000 | T 203.905.4500

Holland & Knight LLP | www.hklaw.com

May 6, 2025

Hubbell Incorporated

40 Waterview Drive

Shelton, Connecticut 06484-1000

Re: Registration Statement on Form S-8 for the Hubbell Incorporated Incentive Award Plan

Ladies and Gentlemen,

On or about the date hereof, Hubbell Incorporated, a Connecticut corporation (the “Company”), transmitted for filing with the Securities and Exchange Commission (the “Commission”) a Registration Statement on Form S-8 (the “Registration Statement”) under the Securities Act of 1933, as amended (the “Act”). The Registration Statement relates to the registration by the Company of 620,000 shares (the “Shares”) of the Company’s common stock, par value $0.01 per share (“Common Stock”), that may be issued under the Hubbell Incorporated Incentive Award Plan (the “Plan”). We have acted as counsel to the Company in connection with the preparation and filing of the Registration Statement.

In connection therewith, we have examined and relied upon the original or a copy, certified or otherwise identified to our satisfaction, of: (i) the Company’s Amended and Restated Certificate of Incorporation, as amended and restated to the date hereof (the “Charter”), and Amended and Restated By-Laws, as amended and restated to the date hereof; (ii) records of corporate proceedings of the Company related to the Plan; (iii) the Registration Statement and exhibits thereto; and (iv) such other documents, instruments and records as we have deemed necessary for the expression of the opinions contained herein. In making the foregoing examinations, we have relied, without investigation, on each of the following assumptions: (a) the legal capacity of each natural person to take all actions required of each such person in connection with the Registration Statement and the registration, issuance and sale of the Shares, (b) the genuineness of all signatures, the completeness of all documents submitted to us, the authenticity of all documents reviewed by us as originals, the conformity to original documents of all documents reviewed by us as duplicates or certified or conformed photocopies, (c) as to matters of fact, the truthfulness, accuracy and completeness of the information, representations and warranties of the Company made in the Registration Statement and in the records, documents, instruments, certificates and statements we have reviewed, (d) the due execution and delivery of all documents (except that no such assumption is made as to the Company) where due execution and delivery are a prerequisite to the effectiveness thereof, (e) that there has been no undisclosed waiver of any right, remedy or provision contained in such documents and (f) that the total number of shares of common stock issued and outstanding after the issuance of any of the Shares will not exceed the number of shares of common stock that the Company then has the authority to issue under the Charter. As to various questions of fact material to this opinion, we have relied, to the extent we deemed reasonably appropriate, upon statements and representations of officers or directors of the Company and upon documents, records and instruments furnished to us by the Company, without independently checking or verifying the accuracy of such documents, records and instruments.

Based upon the foregoing examination, and subject to the assumptions, qualifications and limitations stated herein, and assuming that (i) the Company reserves an adequate number of authorized and unissued shares of Common Stock available for issuance pursuant to the Plan and (ii) adequate consideration, if any, for the Shares is actually received by the Company and the Shares are issued pursuant to the Plan in accordance with the terms of the Plan, we are of the opinion that the Shares will be duly authorized, validly issued, fully paid and nonassessable.

This opinion is rendered solely in connection with the filing of the Registration Statement, is limited to the matters stated herein, and no opinions may be implied or inferred beyond the matters expressly stated herein. This opinion may not be relied upon for any other purpose without our prior written consent in each instance. Further, no portion of this letter may be quoted, circulated or referred to in any other document for any other purpose without our prior written consent.