X0306 4 2021-08-09 0 0001669811 Donnelley Financial Solutions, Inc. DFIN 0001464929 Leib Daniel C/O DONNELLEY FINANCIAL SOLUTIONS 35 WEST WACKER DRIVE CHICAGO IL 60601 1 1 0 0 Chief Executive Officer Common Stock 2021-08-09 4 S 0 31822 33.8315 D 476791 D Common Stock 2021-08-10 4 S 0 3178 33.4991 D 473613 D The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on June 2, 2021. The reported price represents a weighted average sale price. The range of prices at which common stock was purchased was $33.41 to $34.30 per share. The Reporting Person undertakes to provide to the staff, the issuer or a security holder full information regarding the number of shares purchased at each separate price. The reported price represents a weighted average sale price. The range of prices at which common stock was purchased was $33.82 to $33.07 per share. The Reporting Person undertakes to provide to the staff, the issuer or a security holder full information regarding the number of shares purchased at each separate price. Includes 307,746 shares held directly and 165,867 restricted stock units. Jennifer Reiners, pursuant to power of attorney 2021-08-11