Exhibit 5.1

mwe.com

May 1, 2020

My Size, Inc.

4 Hayarden St.

P.O.B. 1026,

Airport City, 7010000

Israel

Ladies and Gentlemen:

We are rendering this opinion in connection with the Registration Statement on Form S-1 (the “Registration Statement”), to be filed by My Size, Inc., a Delaware corporation (the “Company”), with the Securities and Exchange Commission in connection with the registration under the Securities Act of 1933, as amended, for resale of an aggregate of up to 545,689 shares (the “Shares”) of common stock, par value $0.001 per share, of the Company (the “Common Stock”) consisting of (i) 514,801 shares of Common Stock issuable upon the exercise of warrants (the “Investor Warrants”) issued in a private placement in January 2020 (the “January 2020 Private Placement”), and (ii) 30,888 shares of Common Stock issuable upon the exercise of placement agent warrants (the “Placement Agent Warrants”, and together with the Investor Warrants, the “Warrants”) issued in connection with the January 2020 Private Placement.

We have examined: (i) the Registration Statement; (ii) the Amended and Restated Certificate of Incorporation certified by the Secretary of State of the State of Delaware as of March 22, 2017, as amended by the Certificate of Amendment of Amended and Restated Certificate of Incorporation certified by the Secretary of State of the State of Delaware as of February 15, 2018, as further amended by the Certificate of Amendment of Amended and Restated Certificate of Incorporation certified by the Secretary of State of the State of Delaware as of November 15, 2019 (the “Certificate of Incorporation”); (iii) the Second Amended and Restated By-Laws of the Company dated April 18, 2018; (iv) the Warrants; and (v) resolutions relating to the authorization and issuance of the Warrants and the Shares and the registration of the Shares with the Commission on the Registration Statement adopted by the resolutions adopted as of January 14, 2020 by the Board of Directors of the Company and as of January 15, 2020 by the Pricing Committee of the Board of Directors of the Company.

In addition to the examination outlined above, we have conferred with various officers of the Company and have ascertained or verified, to our satisfaction, such additional facts as we deemed necessary or appropriate for the purposes of this opinion. In our examination, we have assumed the authenticity of all documents submitted to us as originals, the conformity to the original documents of all documents submitted to us as copies, the genuineness of all signatures on documents reviewed by us and the legal capacity of natural persons. For purposes of our opinion herein with respect to the Shares, we have assumed that at the time of exercise or conversion into such Shares following the date hereof, a sufficient number of shares of authorized Common Stock of the Company will be authorized and available for issuance under the Certificate of Incorporation as then in effect.

Based on the foregoing, and assuming that the full consideration for each share issuable upon exercise of the Warrants is received by the Company, and the Warrants are exercised, in accordance with the terms of the Warrants, it is our opinion that the Shares covered by the Registration Statement will, when issued, be validly issued and outstanding, fully paid and nonassessable.

We do not express any opinion herein concerning any law other than the General Corporation Law of the State of Delaware.

We consent to the filing of this opinion as an exhibit to the Registration Statement and we consent to the use of our name wherever it appears in the Registration Statement. In giving this consent, we do not hereby admit that we come within the category of persons whose consent is required under Section 7 of the Securities Act of 1933, as amended, or the rules and regulations of the Securities and Exchange Commission thereunder.

Sincerely,

/s/ McDermott Will & Emery LLP

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