EX-5.1

Exhibit 5.1

LOGO

1401 Eye Street NW, Suite 800, Washington, DC 20005 • (202) 783-3300

September 7, 2023

Board of Directors

FiscalNote Holdings, Inc.

1201 Pennsylvania Avenue NW, 6^th Floor

Washington, D.C. 20004

Ladies and Gentlemen:

We are acting as counsel to FiscalNote Holdings, Inc., a Delaware corporation (the “Company”), in connection with its registration statement on Form S-3 (the “Registration Statement”) filed with the Securities and Exchange Commission (the “Commission”) relating to the resale of up to 11,215,000 shares (the “Shares”) of the Company’s Class A Common Stock, par value $0.0001 per share (the “Common Stock”), issuable upon the conversion of that certain 7.50% Senior Subordinated Convertible Note (the “Note”) by the holder thereof (the “Holder”), all of which Shares are to be sold by the selling stockholder named in the Registration Statement. The Shares are to be issued to the Holder pursuant to the terms and conditions of the Note. This opinion letter is furnished to you at your request to enable you to fulfill the requirements of Item 601(b)(5) of Regulation S-K, 17 C.F.R. § 229.601(b)(5), in connection with the Registration Statement.

For purposes of this opinion letter, we have examined copies of such agreements, instruments and documents as we have deemed an appropriate basis on which to render the opinion hereinafter expressed. In our examination of the aforesaid documents, we have assumed the genuineness of all signatures, the legal capacity of all natural persons, the accuracy and completeness of all documents submitted to us, the authenticity of all original documents, and the conformity to authentic original documents of all documents submitted to us as copies (including electronic copies). As to all matters of fact, we have relied on the representations and statements of fact made in the documents so reviewed, and we have not independently established the facts so relied on. This opinion letter is given, and all statements herein are made, in the context of the foregoing.

For purposes of this opinion letter, we have assumed that (i) at the time of offer, issuance and sale of any of the Shares, (x) the Registration Statement (and any amendments thereto (including post-effective amendments)) will have been declared effective under the Securities Act of 1933, as amended (the “Act”), and no stop order of the Commission suspending its effectiveness or the use of the prospectus contained therein or any prospectus supplement relating thereto will have been issued and remain in effect, (y) the Company will have had a sufficient number of authorized but unissued shares of Common Stock under the Certificate of Incorporation of the Company not otherwise reserved for issuance, and (z) there will not have occurred any change in law affecting the validity or enforceability of the Note; (ii) the Shares will have been acquired by the Holder pursuant to the terms and conditions set forth in the Note; and (iii) the Company will have remained a Delaware corporation.

This opinion letter is based as to matters of law solely on the applicable provisions of the Delaware General Corporation Law, as amended, and currently in effect. We express no opinion herein as to any other laws, statutes, ordinances, rules, or regulations (and in particular, we express no opinion as to any effect that such other laws, statutes, ordinances, rules, or regulations may have on the opinions expressed herein).

polsinelli.com

Atlanta Boston Chicago Dallas Denver Houston Kansas City Los Angeles Miami Nashville New York Phoenix St. Louis San Francisco Seattle Silicon Valley Washington, D.C. Wilmington

Polsinelli PC, Polsinelli LLP in California