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