Exhibit 5.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in this Registration Statement on Form F-10 of our reports dated March 29, 2017, relating to the consolidated financial statements of MAG Silver Corp. and subsidiaries (the “Company”) and the effectiveness of the Company’s internal control over financial reporting appearing in the Annual Report on Form 40-F of the Company for the year ended December 31, 2016, and to the reference to us under the heading “Interest of Experts” in the Prospectus, which is part of this Registration Statement.

/s/ Deloitte LLP

Chartered Professional Accountants

Vancouver, Canada

January 19, 2018