Steve Buscemi Enoch "Nucky" Thompson Actor Kelly Macdonald Margaret Schroeder Actor Michael Shannon Nelson Van Alden Actor Shea Whigham Elias Thompson Actor Anthony Laciura Eddie Kessler Actor Stephen Graham Al Capone Actor Michael Stuhlbarg Arnold Rothstein Actor Vincent Piazza Lucky Luciano Actor Paul Sparks Mickey Doyle Actor Michael Kenneth Williams Chalky White Actor Gretchen Mol Gillian Actor Jack Huston Richard Harrow Actor Jeffrey Wright Dr. Valentin Narcisse Actor Ron Livingston Roy Phillips Actor Stephen Root Gaston Means Guest Star Brian Geraghty Agent Warren Knox Guest Star Domenick Lombardozzi Ralph Capone Guest Star Arron Shiver Dean O'Banion Guest Star Morgan Spector Frank Capone Guest Star Terence Winter Executive Producer Martin Scorsese Executive Producer Timothy Van Patten Executive Producer Stephen Levinson Executive Producer Mark Wahlberg Executive Producer