EX-5.1

Exhibit 5.1

LOGO

January 24, 2019

Canopy Growth Corporation

1 Hershey Drive

Smiths Falls, Ontario K7A 0A8

Ladies and Gentlemen:

Re: Canopy

Growth Corporation - Registration Statement on Form S-8

We have acted as counsel to Canopy Growth Corporation, a corporation incorporated pursuant to the federal laws of Canada (the “Company”), in connection with a Registration Statement on Form S-8 filed on or about January 23, 2019 with the Securities and Exchange Commission (the “Registration Statement”) under the United States Securities Act of 1933, as amended (the “Act”) for the purpose of registering the issuance of: (i) 51,047,572 common shares of the Company (the “Shares”) that may be issued upon exercise or redemption of awards (the “Awards”) granted or issued under the Company’s Amended and Restated Omnibus Incentive Plan (the “Plan”) and (ii) 400,000 Shares issuable under the Canopy Growth Corporation Employee Stock Purchase Plan (the “ESPP”).

In rendering this opinion, we have examined: (i) the Plan; (ii) the ESPP; (iii) certain resolutions of the Board of Directors of the Company evidencing the corporate proceedings taken by the Company to approve the filing of the Registration Statement and to authorize the issuance of the Shares upon the exercise or redemption of Awards and the Shares issuable under the ESPP; (iv), the Articles of the Company, as amended and (v) such other documents as we have deemed appropriate or necessary as a basis for the opinion hereinafter expressed.

In rendering the opinion expressed below, we assumed the legal capacity of natural persons signing or delivering any instrument, the authenticity of all documents and records examined, the conformity with the original documents of all documents submitted to us as copies, and the genuineness of all signatures.

Based upon and subject to the foregoing, and such legal considerations as we deem relevant, we are of the opinion that the Shares, when issued upon the valid exercise or redemption of Awards in accordance with the terms of the Plan, including, in each case, receipt by the Company of payment in full for the Shares in respect of which such Awards are exercised or redeemed or upon issuance in accordance with the terms of the ESPP, as the case may be, such Shares will be validly issued, fully paid and non-assessable.

The foregoing opinion is based solely on the present laws and applicable regulations of the Province of Ontario and the laws of Canada in force therein. We express no opinion as to matters involving the laws of any other jurisdiction.