Exhibit 5.1

Troutman Pepper Hamilton Sanders LLP 1001 Haxall Point, Ste. 1500 Richmond, VA 23219   troutman.com

August 6, 2021

Ensysce Biosciences, Inc.

7946 Ivanhoe Avenue,

Suite 201

La Jolla, California 92037

Ladies and Gentlemen:

We are acting as counsel to Ensysce Biosciences, Inc., a Delaware corporation (the “Company”), in connection with the registration statement on Form S-1 (the “Registration Statement”), filed with the Securities and Exchange Commission (the “SEC”), including a related prospectus included in the Registration Statement (the “Prospectus”), on August 6, 2021, relating to the registration under the Securities Act of 1933, as amended (the “Act”), of (a) the issuance of shares of common stock, $0.0001 par value per share (the “Common Stock”), of the Company upon the exercise of warrants issued by the Company, and (b) the resale of Common Stock and warrants issued by the Company held by certain stockholders and holders of outstanding warrants of the Company, as follows:

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The Public Warrants were issued pursuant to a warrant agreement dated December 1, 2017 (the “Public Warrant Agreement”). The Private Placement Warrants were originally issued pursuant to a Warrant Agreement dated as of December 1, 2017. On June 7, 2021, each of the holders of the Private Placement Warrants exchanged their warrants for new private warrants which were on the same terms as the Private Placement Warrants, except that they were not issued under the Private Placement Warrant Agreement and were non-transferrable except to permitted transferees (the “Private Placement Warrant Agreement”). The Email Agreement Warrants and Email Agreement Shares were issued pursuant to the Email Agreement dated January 31, 2021, as amended by the First Amendment to the Email Agreement, dated June 7, 2021 (the “Email Agreement”). The Expense Advancement Agreement Warrants and the Expense Advancement Agreement Loan Warrants were issued in exchange for outstanding loans under the Expense Advancement Agreement dated December 1, 2017, as amended (the “Expense Advancement Agreement”). On June 7, 2021, the holders of the Expense Advancement Agreement Warrants exchanged their warrants for new private warrants which were on the same terms as the Expense Advancement Agreement Warrants except that they were non-transferable except to permitted transferees. The GTWY Expense Advancement Agreement Warrants were issued pursuant to an unsecured promissory note issued to GTWY Holdings Limited, a Canadian corporation, on December 5, 2019, as amended on January 31, 2021 (the “GTWY Promissory Note”), which permitted conversion of all or a portion of the GTWY Promissory Note into warrants of the Company. On June 7, 2021, each of the holders of the GTWY Expense Advancement Agreement Warrants exchanged their warrants for new private warrants which were on the same terms as the GTWY Expense Advancement Agreement Warrants except that they were non-transferable except to permitted transferees. The GEM Agreement Warrants were issued to GEM Yield Bahamas Limited (“GYBL”) under the terms of the Share Purchase Agreement between the Company, GEM Global Yield LLC SCS (“GEM Global”) and GYBL, dated as of December 29, 2020, including a Registration Rights Agreement between the same parties and dated as of the same date (the “GEM Agreement”). The Consultant Warrants and Consultant Shares are issuable pursuant to certain agreements with the consultants dated as of July 22, 2021 (the “Consultant Warrant and Share Agreements”).

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This opinion is being furnished in accordance with the requirements of Item 16 of Form S-1 and Item 601(b)(5)(i) of Regulation S-K.

For purposes of the opinions we express below, we have examined the originals or copies, certified or otherwise identified, of (i) the Registration Statement, (ii) the Company’s third amended and restated certificate of incorporation (the “Certificate of Incorporation”) and the amended and restated bylaws of the Company, each as amended and/or restated to date, (iii) the Email Agreement, (iv) the Expense Advancement Agreement, (v) the GTWY Promissory Note, (vi) the Public Warrant Agreement, (vii) the Private Placement Warrant Agreement, (viii) the GEM Agreement, (ix) the Consultant Warrant and Share Agreements, and (x) such other instruments and documents as we considered appropriate for purposes of the opinions hereafter expressed.

In connection with rendering the opinions set forth below, we have assumed without verification (i) the authenticity of all documents submitted to us as originals, (ii) the conformity to the originals of all documents submitted as certified, photostatic or electronic copies and the authenticity of the originals thereof, (iii) the legal capacity of natural persons, (iv) the genuineness of signatures not witnessed by us, including electronic signatures, (v) the due authorization, execution and delivery of all documents by all parties, other than the Company, and the validity, binding effect and enforceability thereof, and (vi) the truth, accuracy and completeness of the information, representations and warranties contained in the records, documents, instruments and certificates we have reviewed.

With respect to the Warrants and Warrant Shares, we express no opinion to the extent that, notwithstanding the Company’s current reservation of shares of Common Stock, future issuances of securities of the Company and/or antidilution adjustments to outstanding securities of the Company may cause the number of shares issuable upon exercise of the Warrants for more shares of Common Stock than the number that then remain authorized but unissued. Further, we have assumed the exercise prices of the Warrants will not be adjusted to an amount below the par value per share of the shares of Common Stock.

As to factual matters, we have relied upon the documents furnished to us by the Company, the certificates and other comparable documents of officers and representatives of the Company, statements made to us in discussions with the Company’s management and certificates of public officials, without independent verification of their accuracy.

We are opining herein as to the General Corporation Law of the State of Delaware and we express no opinion with respect to any other laws. We are not opining as to the applicability thereto, or the effect thereon, of the laws of any other jurisdiction or, in the case of Delaware, any other laws, or as to matters of municipal law or the laws of any local agencies within any states (including “blue sky” or other state securities laws). With regard to our opinion concerning the Warrants constituting valid and binding obligations of the Company:

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Based on the foregoing and in reliance thereon, and subject to the limitations, qualifications, assumptions, exceptions and other matters set forth herein, we are of the opinion that:

Our opinion is as of the date hereof and we have no responsibility to update this opinion for events and circumstances occurring after the date hereof or as to facts relating to prior events that are subsequently brought to our attention and we disavow any undertaking to advise you of any changes in law.

We hereby consent to the filing of this opinion letter as Exhibit 5.1 to the Registration Statement and to the use of our name under the caption “Legal Matters” in the Registration Statement and in the Prospectus forming a part thereof and any supplement thereto. In giving this consent, we do not thereby admit that we are within the category of persons whose consent is required under Section 7 of the Act or the rules and regulations of the Commission promulgated thereunder.