The character of Kate Callahan, played by Jennifer Love Hewitt, was introduced in Season 13 of Criminal Minds and departed the show in Season 15. She did not have a direct replacement. The show concluded with Season 15, and no further seasons or spin-offs have been announced.
While there were many other characters throughout the show's run, including A.J. Cook, Matthew Gray Gubler, Shemar Moore, and Kirsten Vangsness, there was no specific character designated to replace Kate.
