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