Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

Eagle Pharmaceuticals, Inc.

Woodcliff Lake, New Jersey

We hereby consent to the incorporation by reference in the Registration Statement on Form S--3 (No. 333-202592) and Form S-8 (Nos. 333-228876, 333-216839, 333-213683, 333-206729 and 333-194056) of Eagle Pharmaceuticals, Inc. (the “Company”) of our reports dated February 28, 2019, relating to the consolidated financial statements, and the effectiveness of the Company’s internal control over financial reporting, which appear in this Form 10-K.

/s/ BDO USA, LLP

Woodbridge, New Jersey

February 28, 2019