Over the course of 33 seasons and 662 episodes, One Chicago has experienced a good number of cast exits, and as for the 20242025 TV season, six actors and actresses across the three shows will not be returning to the franchise. The One Chicago universe was established in October 2012 with the premiere of Chicago Fire, with Chicago PD debuting in January 2014 and Chicago Med arriving in November 2017 (a third spinoff, Chicago Justice, was released in March 2017 but was canceled after one season). All three procedural TV series are still going strong, despite their various casting changes.

https://screenrant.com/one-chicago-characters-actor-not-returning-2024-2025-season/