Exhibit 99.1 DFIN Reports Third-Quarter 2024 Results CHICAGO – October 31, 2024 – Donnelley Financial Solutions, Inc. (NYSE: DFIN) (the "Company" or "DFIN") today reported financial results for the third quarter of 2024. Highlights for the third quarter of 2024: • Record third-quarter software solutions net sales of $82.2 million, an increase of 12.3%, or 13.6% on an organic basis (a), from the third quarter of 2023; Software solutions net sales accounted for 45.8% of total net sales, up from 40.7% in the t ...