Elle Fanning Nikola Trumbo
Bryan Cranston Dalton Trumbo
Audrey Hepburn Princess Ann (archive footage) (uncredited)
Cary Grant Self (archive footage) (uncredited)
John Goodman Frank King
Helen Mirren Hedda Hopper
Diane Lane Cleo Trumbo
Lucille Ball Self (archive footage) (voice) (uncredited)
Eddie Albert Irving Radovich in Roman Holiday (archive footage) (uncredited)
Michael Stuhlbarg Edward G. Robinson
Jean Simmons Varinia (archive footage) (uncredited)
Deborah Kerr Self (archive footage) (uncredited)
Robert Taylor Self (archive footage) (uncredited)
Danny Kaye Self (archive footage) (uncredited)
Louis C.K. Arlen Hird
Alan Tudyk Ian McLellan Hunter
James Garner Self (archive footage) (uncredited)
Stephen Root Hymie King
Dalton Trumbo Himself (archive footage)
Dean O'Gorman Kirk Douglas
Laurence Olivier Crassus (archive footage) (uncredited)
Gregory Peck Joe Bradley (archive footage) (uncredited)
Madison Wolfe Niki Trumbo (age 8-11)
Roger Bart Buddy Ross
Adewale Akinnuoye-Agbaje Virgil Brooks
John Neisler Jury Foreman
Ronald Reagan Self (archive footage) (uncredited)
Shivani Rawat Producer
James DuMont J. Parnell Thomas
Johnny Sneed Robert Stripling
Lauren Bacall Self (archive footage) (uncredited)
Michael London Producer
John Getz Sam Wood
Jaclyn Bethany Starlet (uncredited)
Janice Williams Producer
Mark Ricker Production Design
David James Elliott John Wayne
Mark Harelik Ed Muhl, Edward 'Ed' Muhl
Laura Flannery Party Goer
John McNamara Screenplay, Producer
Richard Portnow Louis B. Mayer
Jay Roach Director, Producer
Dan Bakkedahl Roy Brewer
Mattie Liptak Chris Trumbo (Age 13-17)
Jeri Habberstad Stunt Double
Geoffrey Haley "A" Camera Operator, Steadicam Operator
Sean Bridgers Jeff Krandall
Rio Hackford Reporter
Christian Berkel Otto Preminger
George Parra First Assistant Director
Kevin Kelly Brown Producer
Gary Archer Prosthetics
Veronica Parks Showgirl (uncredited)
Daniel Orlandi Costume Designer
Peter MacKenzie Robert Kenny
Jesse Rosenthal Art Direction
Toby Nichols Chris Trumbo (age 6-10) (as Tobias McDowell Nichols)
Michelle Graham Co-Producer
Rhonda Laizer Trumbo Friend (uncredited)
Monica Levinson Producer, Unit Production Manager
Heather Arthur Stunt Coordinator
Meghan Wolfe Mitzi Trumbo (age 6-8)
Lisa Marinaccio Art Direction
Theodore Shapiro Original Music Composer
Suzanne LaChasse Showgirl (uncredited)
Dane Rhodes Reporter
Scott August Second Assistant Director
David Rubin Casting
Alan Baumgarten Editor
Anne Speed Juror (uncredited)
Garrett Hines Andrew Hird
Laurie Lieser Associate Producer