Exhibit 5.1

SICHENZIA ROSS FRIEDMAN FERENCE LLP

Attorneys At Law

61 Broadway, 32nd Floor

New York, New York 10006

Telephone: (212) 930-9700

Facsimile: (212) 930-9725

February 10, 2015

VIA ELECTRONIC TRANSMISSION

Securities and Exchange Commission

100 F Street, N.E.

Washington, DC 20549

Form S-8 Registration Statement

Ladies and Gentlemen:

We refer to the above-captioned registration statement on Form S-8 (the “Registration Statement”) under the Securities Act of 1933, as amended (the “Act”), filed by Tonix Pharmaceuticals Holding Corp., a Nevada corporation (the “Company”), with the Securities and Exchange Commission.

We have examined the originals, photocopies, certified copies or other evidence of such records of the Company, certificates of officers of the Company and public officials, and other documents as we have deemed relevant and necessary as a basis for the opinion hereinafter expressed. In such examination, we have assumed the genuineness of all signatures, the authenticity of all documents submitted to us as certified copies or photocopies and the authenticity of the originals of such latter documents.

Based on our examination mentioned above, we are of the opinion that the securities being registered to be sold pursuant to the Registration Statement are duly authorized and will be, when sold in the manner described in the Registration Statement, legally and validly issued, and fully paid and non-assessable.

We hereby consent to the filing of this opinion as Exhibit 5.01 to the Registration Statement. In giving the foregoing 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 Securities and Exchange Commission.