Exhibit 5.1

	811 Main Street, Suite 3700 Houston, TX 77002 Tel: +1.713.546.5400 Fax: +1.713.546.5401 www.lw.com
November 5, 2021	FIRM / AFFILIATE OFFICES AustinMilan BeijingMoscow BostonMunich BrusselsNew York Century CityOrange County ChicagoParis DubaiRiyadh DüsseldorfSan Diego FrankfurtSan Francisco HamburgSeoul Hong KongShanghai HoustonSilicon Valley LondonSingapore Los AngelesTokyo MadridWashington, D.C.

Science 37 Holdings, Inc.

600 Corporate Pointe, Suite 320

Culver City, California 90230

Re: Science 37 Holdings, Inc. – Registration Statement on Form S-1

To the addressees set forth above:

We have acted as special counsel to Science 37 Holdings, Inc., a Delaware corporation (the “Company”), in connection with its filing on the date hereof with the Securities and Exchange Commission (the “Commission”) of a registration statement on Form S-1 (the “Registration Statement”) under the Securities Act of 1933, as amended (the “Act”), relating to the registration of the offer and sale from time to time of (i) 20,000,000 outstanding shares (the “PIPE Shares”) of common stock, par value $0.0001 per share (the “common stock”), of the Company, in each case, by the selling securityholders named in the Registration Statement, (ii) 2,002,260 shares of common stock (the “Founder Shares”) issued in connection with the consummation of the Company’s business combination with LifeSci Acquisition II Corp. (the “Business Combination”), by the selling securityholders named in the Registration Statement and (iii) up to 67,336,621 shares of common stock issued or issuable to certain former stockholders and other securityholders of the Company in connection with or as a result of the consummation of the Business Combination, consisting of (a) up to 54,836,621 shares of common stock (the “Resale Shares”) and (b) up to 12,500,000 shares of common stock (the “Earn-out Shares”) that certain Company stockholders have the contingent right to receive upon the achievement of certain stock price-based vesting conditions pursuant to that certain Agreement and Plan of Merger, dated as of May 6, 2021, by and among the Company (formerly known as LifeSci Acquisition II Corp.), LifeSci Acquisition II Merger Corp. and Science 37, Inc., a Delaware Corporation (the “Merger 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 related prospectus or prospectus supplement (collectively, the “Prospectus”) other than as expressly stated herein with respect to the issue of PIPE Shares, the Founder Shares, the Resale Shares and the Earn-out Shares.

November 5, 2021

Page 2

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 the General Corporation Law of the State of Delaware (the “DGCL”) and, with respect to the opinions set forth in paragraph 3 below, the internal laws of the State of New York, and we express no opinion with respect 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 any matters of municipal law or the laws of any local agencies within any state.

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

1. The PIPE Shares, the Founder Shares and the Resale Shares have been duly authorized by all necessary corporate action of the Company and are validly issued, fully paid and nonassessable.

2. When the Earn-out Shares shall have been duly registered on the books of the transfer agent and registrar therefor in the name or on behalf of the recipients thereof, and have been issued by the Company against payment therefor (not less than par value) in the circumstances contemplated by the Registration Statement and the Merger Agreement, the Earn-out Shares will have been duly authorized by all necessary corporate action of the Company and will be validly issued, fully paid and nonassessable.  In rendering the foregoing opinion, we have assumed that the Company will comply with all applicable notice requirements regarding uncertificated shares provided in the DGCL.

Our opinions set forth in numbered paragraph 3 are subject to: (i) the effect of bankruptcy, insolvency, reorganization, preference, fraudulent transfer, moratorium or other similar laws relating to or affecting the rights and remedies of creditors; (ii) the effect of general principles of equity, whether considered in a proceeding in equity or at law (including the possible unavailability of specific performance or injunctive relief), concepts of materiality, reasonableness, good faith and fair dealing, and the discretion of the court before which a proceeding is brought; (iii) the invalidity under certain circumstances under law or court decisions of provisions providing for the indemnification of or contribution to a party with respect to a liability where such indemnification or contribution is contrary to public policy; and (iv) we express no opinion as to (a) any provision for liquidated damages, default interest, late charges, monetary penalties, make-whole premiums or other economic remedies to the extent such provisions are deemed to constitute a penalty, (b) consents to, or restrictions upon, governing law, jurisdiction, venue, arbitration, remedies, or judicial relief, (c) waivers of rights or defenses, (d) any provision requiring the payment of attorneys’ fees, where such payment is contrary to law or public policy, (e) the creation, validity, attachment, perfection, or priority of any lien or security interest, (f) advance waivers of claims, defenses, rights granted by law, or notice, opportunity for hearing, evidentiary requirements, statutes of limitation, trial by jury or at law, or other procedural rights, (g) waivers of broadly or vaguely stated rights, (h) provisions for exclusivity, election or cumulation of rights or remedies, (i) provisions authorizing or validating conclusive or discretionary determinations, (j) grants of

November 5, 2021

Page 3

setoff rights, (k) proxies, powers and trusts, (l) provisions prohibiting, restricting, or requiring consent to assignment or transfer of any right or property, and (m) the severability, if invalid, of provisions to the foregoing effect.

With your consent, we have assumed that the status of the Merger Agreement as the legally valid and binding obligation of the parties will not be affected by any (i) breaches of, or defaults under, agreements or instruments, (ii) violations of statutes, rules, regulations or court or governmental orders or (iii) failures to obtain required consents, approvals or authorizations from, or to make required registrations, declarations or filings with, governmental authorities.

This opinion is for your benefit in connection with the Registration Statement and may be relied upon by you and by persons entitled to rely upon it pursuant to the applicable provisions of the Act.  We consent to your filing this opinion as an exhibit to the Registration Statement and to the reference to our firm contained in the Prospectus under the heading “Legal Matters.”  In giving such consent, we do not thereby 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.

Sincerely,

/s/ Latham & Watkins LLP