Exhibit 23.1
CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
We consent to the reference to our firm under the caption “Experts” in this Registration Statement (Form S-3) and related Prospectus of American Financial Group, Inc. for the
registration of debt securities, common stock, preferred stock, warrants, depository shares, purchase contracts and units and to the incorporation by reference therein of our reports dated February 25, 2021, with respect to the consolidated financial
statements and schedules of American Financial Group, Inc., and the effectiveness of internal control over financial reporting of American Financial Group, Inc., included in its Annual Report (Form 10-K) for the year ended December 31, 2020, filed
with the Securities and Exchange Commission.
Cincinnati, Ohio
February 26, 2021