ICON Public Limited (ICLR) S-8 POS Registration of securities for employees (post-effective amendment)

Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

We consent to the use of our reports dated February 24, 2021, with respect to the consolidated financial statements of ICON plc and subsidiaries, and the effectiveness of internal control over financial reporting, incorporated herein by reference.

/s/ KPMG

Dublin, Ireland

June 30, 2021