| Liev Schreiber | Ray Donovan |
| Eddie Marsan | Terry Donovan |
| Dash Mihok | Bunchy Donovan |
| Pooch Hall | Daryll |
| Kerris Dorsey | Bridget Donovan |
| Graham Rogers | Smitty |
| Jon Voight | Mickey Donovan |
| Kerry Condon | Molly Sullivan |
| Quincy Tyler Bernstine | Detective Perry |
| Kevin Corrigan | Declan Sullivan |
| Lois Smith | Dolores |
| Sheryl Lee Ralph | Claudette |
| Zach Grenier | Ed Feratti |
| Robert Funaro | Lt. Bricker |
| Delaney Williams | R. Gregory Scholl |
| Peter Gerety | James Sullivan |
| Alan Alda | Dr. Arthur Amiot |
| Keren Dukes | Jasmine |
| Nate Mann | Teen Ray Donovan |
| Fady Kerko | Fareed |
| Emily Richardson | Teen Bridget Donovan |
| Nora Cole | Avis |
| Patrick Ryan Wood | Teen Bunchy Donovan |
| Skyler Gallun | Teen Terry Donovan |
| Lev Fer | Teen Gary O'Malley |
| Rami Margron | Frankie Lee |
| Alison Cimmet | Kimberly |
| Suzanne Grodner | Mrs. Scholl |
| Sandra Elizabeth Rodriguez | Attorney |