George Clooney (Michael Clayton), Sean Cullen (Gene Clayton), Tom Wilkinson (Arthur Edens), Tilda Swinton (Karen Crowder), Sydney Pollack (Marty Bach), Michael O'Keefe (Barry Grissom), Ken Howard (Don Jeffries), Denis O'Hare (Mr. Greer), Julie White (Mrs. Greer), Robert Prescott (Mr. Verne), David Zayas (Detective Dalberto), Amy Hargreaves (Interviewerin), Bill Raymond (Gabe Zabel), David Lansbury (Timmy Clayton), Austin Williams (Henry Clayton), Frank Wood (Gerald), Douglas McGrath (Jeff Gaffney), Kevin Hagan (Raymond Clayton), Pamela Gray (Cindy Bach), Merritt Wever (Anna), Jennifer Van Dyck (Ivy), Richard Hecht (Auktionator), Skip Sudduth (Jerry Dante), Susan Pellegrino (Sekretärin), Terry Serpico (Mr. Iker), Wai Chan (Chinesischer Händler), Alberto Vazquez (Spieler #1), Brian Koppelman (Spieler #2), Christopher Mann (Lieutenant Elston), Rachel Black (Maude), Maggie Siff (Anwalt #1), Sharon Washington (Pam), Remy Auberjonois (Fünftes Jahr), Neal Huff (First Associate)