| Al Pacino | Roy Cohn | |
| Emma Thompson | Nurse Emily/ | |
| Jeffrey Wright | Belize/ | |
| Ben Shenkman | Louis Ironson | |
| James Cromwell | Roy's Doctor | |
| Pete Macnamara | Oak Room Patron |
| Meryl Streep | Ethel Rosenberg/ | |
| Mary-Louise Parker | Harper Pitt | |
| Justin Kirk | Prior Walter/ | |
| Patrick Wilson | Joe Pitt | |
| James Babbin | Plaza Hotel Waiter | |
| Paul Burton Wilson | Bar Patron |