Exhibit 23.3

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in this Registration Statement on Form S-4 of FB Financial Corporation of our report dated March 16, 2020 relating to the consolidated financial statements appearing in the Annual Report on Form 10-K of Franklin Financial Network, Inc. for the year ended December 31, 2019, and to the reference to us under the heading “Experts” in the prospectus.

/s/ Crowe LLP

Franklin, Tennessee

March 25, 2020