| Kirk Acevedo | Miguel Alvarez |
| Ernie Hudson | Warden Leo Glynn |
| Terry Kinney | Tim McManus |
| Rita Moreno | Sister Peter Marie Reimondo |
| Harold Perrineau | Augustus Hill |
| J.K. Simmons | Vern Schillinger |
| Lee Tergesen | Tobias Beecher |
| Eamonn Walker | Kareem Said |
| Dean Winters | Ryan O'Reily |
| Adewale Akinnuoye-Agbaje | Simon Adebisi |
| Edie Falco | Officer Diane Whittlesey |
| George Morfogen | Bob Rebadow |
| Luna Lauren Velez | Dr. Gloria Nathan
(as Lauren Velez) |
| BD Wong | Father Ray Mukada |
| Zeljko Ivanek | Governor James Devlin |
| Zakes Mokae | Kipekemie Jara |
| Christopher Meloni | Chris Keller |
| Kathryn Erbe | Shirley Bellinger |
| Luis Guzmán | Raoul 'El Cid' Hernandez
(as Luis Guzman) |
| David Lansbury | Robert Sippel |
| Eddie Malavarca | Peter Schibetta |
| Mark Margolis | Antonio Nappa |
| J.D. Williams | Kenny Wangler |
| Bill Fagerbakke | Officer Karl Metzger |
| Scott William Winters | Cyril O'Reily |
| Granville Adams | Zahir Arif |
| Craig muMs Grant | Poet
(as muMs) |
| Tom Mardirosian | Agamemnon Busmalis |
| Evan Seinfeld | Jaz Hoyt |
| Lexington Alexander | Junior Pierce
(as Malé 'BigX' Alexander) |
| Rod Brogan | Frances Hansell |
| Bryan Callen | Jonathan Coushaine |
| Sean Dugan | Timmy Kirk |
| Tim Hopper | Rick Donn |
| Ray Iannicelli | Officer Roger Brese |
| Leif Riddell | Mark Mack |
| Otto Sanchez | Chico Guerra |
| Nelson Vasquez | Officer Eugene Rivera |
| Chuck Zito | Chucky Pancamo |
| Ali Merhi | Luis Batista |
| Frank Bonsangue | Sicilian Crew
(uncredited) |
| Brett Gillen | Philip Featherstone
(uncredited) |
| Dan Koko | Thug #1
(uncredited) |
| Robert Philip Marcus | Aryan
(uncredited) |
| Todo Segalla | Inmate
(uncredited) |
| Jack Serra | Officer Ricotta
(uncredited) |