X0508 4 2026-02-26 0001669811 Donnelley Financial Solutions, Inc. DFIN 0001464929 Leib Daniel C/O DONNELLEY FINANCIAL SOLUTIONS 391 STEEL WAY LANCASTER PA 17601 true true false false Chief Executive Officer true Common Stock 2026-02-26 4 S false 10000 50.3587 D 568181 D The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 11, 2025. The reported price represents a weighted average sale price. The range of prices at which common stock was sold was $50.01 to $50.85 per share. The Reporting Person undertakes to provide to the staff, the issuer or a security holder full information regarding the number of shares sold at each separate price. Includes 443,953 shares held directly, 75,770 restricted stock unit, and 48,458 earned performance share units with additional service-based vesting. William Zola, pursuant to power of attorney 2026-03-02