George Clooney (Michael Clayton), Tom Wilkinson (Arthur Edens), Tilda Swinton (Karen Crowder), Sydney Pollack (Marty Bach), Michael O'Keefe (Barry Grissom), Ken Howard (Don Jeffries), Sean Cullen (Gene Clayton) more..., Merritt Wever (Anna), Austin Williams (Henry Clayton), Robert Prescott (Mr. Verne), Terry Serpico (Mr. Iker), David Lansbury (Timmy Clayton), Bill Raymond (Gabe Zabel), David Zayas (Detective Dalberto), Christopher Mann (Lieutenant Elston), Denis O'Hare (Mr. Greer), Julie White (Mrs. Greer), Frank Wood (Gerald), Heidi Armbruster (Anna's Sister), Sharon Washington (Pam), Danielle Skraastad (Bridget Klein (voice)), Cynthia Mace (Wendy (voice)), Jonathan Walker (Del (voice)), Michael Countryman (Evan (voice)), Douglas McGrath (Jeff Gaffney), Pamela Gray (Cindy Bach), Julia Gibson (Stephanie Clayton), Jennifer Van Dyck (Ivy), Susan McBrien (Jean), Amy Hargreaves (Interviewer), Susan Pellegrino (Secretary), Rachel Black (Maude), Matthew Detmer (Todd), Kevin Hagan (Raymond Clayton), Susan Egbert (Michelle), John Douglas Thompson (Jail Guard), Edward Furs (Milwaukee Captain), Remy Auberjonois (Fifth Year), Katherine Waterston (Third Year), Pun Bandhu (Fourth Year) and others.

James Newton Howard (Original Music Composer), George Clooney (Executive Producer), Ellen Chenoweth (Casting), Steven Soderbergh (Executive Producer), Sydney Pollack (Producer), Anthony Minghella (Executive Producer), Jennifer Fox (Producer) more..., Robert Elswit (Director of Photography), Kevin Thompson (Production Design), Steve Samuels (Producer), Kerry Orent (Producer), James A. Holt (Executive Producer), Sarah Edwards (Costume Design), John Gilroy (Editor), David Davenport (Wardrobe Supervisor), Jennifer Lamb (Stunts), Joanne Lamstein (Stunts), George DeTitta Jr. (Set Decoration), Tony Gilroy (Writer), Chuck Potter (Set Decoration), Waldo Sanchez (Hair Department Head), Christopher Goode (Co-Producer), Chris Bingham (Makeup Department Head), Jerry Popolis (Key Hair Stylist), Paul Cheponis (Set Decoration), Mia Thoen (Key Makeup Artist), Clay Brown (Art Direction), Christine Mayer (Set Decoration), Randall Balsmeyer (Visual Effects Supervisor), Gene Harrison (Stunts), Christopher Goode (Second Unit Director), Jery Hewitt (Stunt Coordinator), Michael Barry (Sound Re-Recording Mixer), Jeff Brink (Special Effects Coordinator), Kevin Zack (Special Effects), Paul P. Soucek (Supervising Sound Editor), Michael Barosky (Sound Mixer), Chris Barnes (Stunts), Andy Kris (Sound Re-Recording Mixer), Norman Douglass (Stunts) and others.