Exhibit 5.1

April 10, 2023

SenesTech, Inc.
234610 N. 19^th Ave., Suite 110

Phoenix, Arizona 85027

Re: SenesTech, Inc. – Registration Statement on Form S-3

Ladies and Gentlemen:

We have acted as counsel to SenesTech, Inc., a Delaware corporation (the “Company”), in connection with its filing of (i) a Registration Statement on Form S-3 (Registration No. 333-261227) under the Securities Act of 1933, as amended (the “Act”), filed with the Securities and Exchange Commission (the “Commission”) on November 19, 2021 and amended on May 4, 2022 and declared effective on May 6, 2022 (the “Registration Statement”), (ii) the form of prospectus forming a part of the Registration Statement (the “Base Prospectus”), and (iii) the prospectus supplement dated April 11, 2023 to be filed pursuant to Rule 424 promulgated under the Act (together with the Base Prospectus, the “Prospectus”). The Prospectus relates to the public offering by the Company of an aggregate of 857,146 shares (“Shares”) of the Company’s common stock, par value $0.001 per share (the “Common Stock”).

The Shares are to be sold pursuant to a securities purchase agreement among the Company and the certain purchasers named therein (the “Purchase Agreement”). This opinion is being furnished in connection with the requirements of Item 601(b)(5) of Regulation S-K under the Act, and no opinion is expressed herein as to any matter pertaining to the contents of the Registration Statement or the Prospectus, other than as expressly stated herein with respect to the issuance of the Securities.

We have examined such matters of fact and questions of law as we have considered appropriate for purposes of this letter. With your consent, 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. The opinions expressed herein are limited to the General Corporation Law of the State of Delaware and, as to the Warrants constituting valid and binding obligations of the Company, the laws of the State of New York. We express no opinion as to the effect on the matters covered by this letter of the laws of any other jurisdiction. We express no opinion herein concerning any state securities or blue sky laws.

In our examination of the foregoing documents, we have assumed 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 copies, the authenticity of the originals of such latter documents and the legal competence of all signatories to such documents.

Based upon the foregoing, and subject to the assumptions, exceptions, qualifications and limitations set forth herein, we are of the opinion that the Shares have been duly authorized for issuance, and when issued against payment therefor pursuant to the terms of the Purchase Agreement, will be validly issued, fully paid and non-assessable.

Please note that we are opining only as to the matters expressly set forth herein, and no opinion should be inferred as to any other matters. This opinion is based upon currently existing statutes, rules, regulations and judicial decisions, as further limited above, and we disclaim any obligation to advise you of any change in any of these sources of law or subsequent legal or factual developments which might affect any matters or opinions set forth herein.

This opinion is rendered to you in connection with the offering described above.

We hereby consent to the filing of this opinion with the Commission and to the reference to our firm in the Prospectus and the Registration Statement. In giving such consent, we do not hereby admit that we are in the category of persons whose consent is required under Section 7 of the Act or the rules and regulations of the Commission thereunder.

Very truly yours,

/s/ Greenberg Traurig, LLP

GREENBERG TRAURIG, LLP