Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in this Registration Statement on Form S-3 of Biogen, Inc. of our report dated February 6, 2020 relating to the financial statements, and the effectiveness of internal control over financial reporting, which appears in Biogen, Inc.’s Annual Report on Form 10-K for the year ended December 31, 2019. We also consent to the reference to us under the heading “Experts” in such Registration Statement

/s/ PricewaterhouseCoopers LLP

Boston, Massachusetts

April 24, 2020