| 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 |
| Betty Buckley | Suzanne Fitzgerald
(as Betty Lynn Buckley) |
| Anthony Chisholm | Burr Redding |
| Kevin Conway | Seamus O'Reilly |
| Christopher Meloni | Chris Keller |
| George Morfogen | Bob Rebadow |
| Luna Lauren Velez | Dr. Gloria Nathan
(as Lauren Vélez) |
| Scott William Winters | Cyril O'Reily |
| BD Wong | Father Ray Mukada |
| Michael Wright | Omar White |
| Granville Adams | Zahir Arif |
| Robert Clohessy | Officer Sean Murphy |
| Mike Doyle | Adam Guenzel |
| Ellen McElduff | Eleanor O'Connor |
| Toni Lewis | Alicia Hinden |
| Tom Mardirosian | Agamemnon Busmalis |
| Craig muMs Grant | Poet
(as muMs) |
| Sandra Purpuro | Katherine McClain |
| Kristin Rohde | Officer Claire Howell |
| David Zayas | Enrique Morales |
| Chuck Zito | Chucky Pancamo |
| Anne Meara | Aunt Brenda O'Reily |
| Gerald Bunsen | Javier Osorio |
| M.G. Gong | Jia Kenmin
(as Michael Delmare) |
| Carl DiMaggio | Officer Len Lopresti |
| Sean Dugan | Timmy Kirk |
| Mtume Gant | Reggie Rawls |
| Carlos Leon | Carlos Martinez |
| John Lurie | Greg Penders |
| Andy Powers | #02W562 Franklin Winthrop |
| Blake Robbins | Officer Dave Brass |
| R.E. Rodgers | James Robson |
| Otto Sanchez | Chico Guerra |
| Philip Scozzarella | Officer Joseph Mineo |
| Evan Seinfeld | Jaz Hoyt |
| Joel West | #99S917 Glen Shupe |
| Whitney Allen | Self |
| Steven Johnson | Prisoner |
| Joseph La Rocca | Correction Officer
(as Joseph LaRocca) |
| Jon M. McDonnell | Prison Guard |
| Mam Smith | Lulu |
| Steven Wishnoff | Tony Masters |
| Frank Bonsangue | Sicilian Crew
(uncredited) |