X0306 4 2021-07-06 0 0001499453 Spirit of Texas Bancshares, Inc. STXB 0001738217 Patel Akash J. 1836 SPIRIT OF TEXAS WAY CONROE TX 77301 1 0 0 0 Common Stock 2021-07-06 4 P 0 88 22.7081 A 185969 D The sale reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on 04/27/2021. Includes 1,500 shares restricted stock units ("RSUs"), which will vest in five equal annual installments beginning on 04/01/2022, 1,000 RSUs, which began vesting in five equal annual installments beginning on 07/01/2021, and 1,000 RSUs, which began vesting in five equal annual installments beginning on 05/23/2020. /s/ By Michael L. Durham as Attorney-in-Fact for Akash J. Patel 2021-07-08