Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the following registration statements (and any amendments thereto):

(1)Form S-8, No. 333-127410

(2) Form S-8, No. 333-127411

(3) Form S-4, No. 333-124303

(4) Form S-8, No. 333-146940

(5) Form S-8, No. 333-154875

(6) Form S-8, No. 333-174538

(7) Form S-8, No. 333-192186

(8)Form S-3, No. 333-222643

of our reports dated March 1, 2018, with respect to the consolidated financial statements and schedule of IAC/InterActiveCorp, and the effectiveness of internal control over financial reporting of IAC/InterActiveCorp, included in this Annual Report (Form 10-K) of IAC/InterActiveCorp for the year ended December 31, 2017.

/s/ ERNST & YOUNG LLP

New York, New York

March 1, 2018