Fiserv (FI) 8-K Audited consolidated financial statements of First Data Corporation

EXHIBIT 23.1

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the Registration Statement Nos.333-145599,333-143191,333-163636,333-188795 and333-231868 on FormS-8,No. 333-229689 on FormS-4, andNo. 333-227436 on FormS-3 of Fiserv, Inc. of our report dated February 26, 2019, with respect to the consolidated financial statements and schedule of First Data Corporation included in this Current Report on Form8-K of Fiserv, Inc.

/s/ Ernst & Young LLP

Atlanta, Georgia

June 7, 2019