EXHIBIT 5.1

Dentons US LLP

1221 Avenue of the Americas

New York, NY 10020-1089

United States

October 6, 2026

Board of Directors

200 West 41st Street, 21st Floor

New York, New York 10036

Ladies and Gentlemen:

We have acted as counsel to Fusemachines Inc. a Delaware corporation (the “Company”), in connection with the registration, offer and sale by certain selling securityholders (the “Selling Securityholders”) named in the Registration Statement (defined below) of up to 7,549,411 shares of Common Stock (the “Resale Shares”), which Resale Shares include (i) up to 1,190,476 shares of Common Stock issuable upon conversion of convertible notes issued pursuant to that certain Securities Purchase Agreement dated August 2, 2026 (the “August 2026 SPA”), which represents 200% of the maximum number of shares of Common Stock currently issuable upon conversion in full of such notes at the initial fixed conversion price of $4.20 per share to account for certain adjustments to the conversion price that may occur pursuant to the terms of such notes (the “Note Shares”); (ii) up to 4,100,000 shares of Common Stock issuable upon exercise of warrants (the “Warrants”) issued pursuant to the August 2026 SPA, which represents 200% of the maximum number of shares of Common Stock currently issuable upon exercise in full of such warrants at the initial fixed exercise price of $4.20 per share to account for certain adjustments to the exercise price that may occur pursuant to the terms of such warrants (the “Warrant Shares”); (iii) 2,138,935 shares of Common Stock issued to certain vendors of the Company pursuant to that certain Securities Purchase Agreement dated September 10, 2026 (the “Vendor Shares”); and (iv) 120,000 shares of Common Stock issued to Fulcrum New Amsterdam LLC (d/b/a Retail Volts) pursuant to the Marketing Services Agreement dated September 21, 2026 (the “Retail Volts Shares”).

The Resale Shares are included in a registration statement on Form S-1 under the Securities Act of 1933, as amended (the “Act”), filed with the Securities and Exchange Commission (the “Commission”) on the date hereof (the “Registration Statement”). This opinion is being furnished in connection with the requirements of Item 601(b)(5) of Regulation S-K under the Securities Act of 1933, as amended (the “Act”), and no opinion is expressed herein as to any matter pertaining to the contents of the Registration Statement or related prospectus or prospectus supplement (collectively, the “Prospectus”), other than as expressly stated herein.

As such counsel, 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. We are opining herein as to General Corporation Law of the State of Delaware, and we express no opinion with respect to any other laws.

Subject to the foregoing and the other matters set forth herein, it is our opinion that, as of the date hereof:

The Resale Shares have been duly authorized by all necessary corporate action of the Company.

When the Warrant Shares initially issuable upon exercise of the Warrants shall have been duly registered on the books of the transfer agent and registrar therefor in the name of or on behalf of the Warrant holders, and have been issued by the Company against payment therefor (not less than par value) in the circumstances contemplated by the Warrants, the Warrant Shares will have been duly authorized by all necessary corporate action of the Company, and will be validly issued, fully paid and nonassessable.

Dentons US LLP

1221 Avenue of the Americas

New York, NY 10020-1089

United States

When the Note Shares initially issuable upon conversion of the convertible notes shall have been duly registered on the books of the transfer agent and registrar therefor in the name of or on behalf of the convertible note holders, and have been issued by the Company in the circumstances contemplated by the convertible notes, the Note Shares will have been duly authorized by all necessary corporate action of the Company, and will be validly issued, fully paid and nonassessable.

	4.	The Vendor Shares have been duly authorized by all necessary corporate action of the Company, and are validly issued, fully paid and nonassessable.

	5.	The Retail Volts Shares have been duly authorized by all necessary corporate action of the Company and, having been issued by the Company against consideration therefor of not less than par value in the circumstances contemplated by the Marketing Services Agreement, are validly issued, fully paid and nonassessable.

The opinions expressed above are subject to bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and other similar laws of general application affecting the rights and remedies of creditors and to general principles of equity.

The foregoing opinion is limited to laws of the State of Delaware corporate law (which includes the Delaware General Corporation Law and applicable provisions of the Delaware constitution, as well as reported judicial opinions interpreting same), and we do not purport to express any opinion on the laws of any other jurisdiction.

We hereby consent to the use of our opinion as an exhibit to the Registration Statement and to the reference to this firm and this opinion under the heading “Legal Matters” in the Registration Statement. In giving such consent, we do not hereby admit that we come within 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/ Dentons US LLP
	Dentons US LLP