| Name (Sort) | Character (Sort) | |
| •Steve Buscemi | played | Enoch 'Nucky' Thompson (24Eps.) |
| •Michael Pitt | played | Jimmy Darmody (12Eps.) |
| •Kelly MacDonald (3) | played | Margaret Schroeder (22Eps.) |
| •Mike Shannon (1) | played | Van Alden (16Eps.) |
| •Shea Whigham | played | Eli Thompson (22Eps.) |
| •Aleksa Palladino | played | Angela Darmody (12Eps.) |
| •Michael Stuhlbarg | played | Arnold Rothstein (19Eps.) |
| •Stephen Graham (1) | played | Al Capone (17Eps.) |
| •Vincent Piazza | played | Lucky Luciano (18Eps.) |
| •Paz de la Huerta | played | Lucy (12Eps.) |
| •Michael K. Williams (3) | played | Chalky White (16Eps.) |
| •Anthony Laciura | played | Louis Kessel (12Eps.) |
| •Paul Sparks | played | Mickey Doyle (20Eps.) |
| •Dabney Coleman | played | Commodore Kaestner (12Eps.) |