Bryan Cranston
Dalton Trumbo
Diane Lane
Cleo Trumbo
Helen Mirren
Hedda Hopper
Elle Fanning
Nikola Trumbo
Louis C.K.
Arlen Hird
John Goodman
Frank King
Michael Stuhlbarg
Edward G. Robinson
David James Elliott
John Wayne
Roger Bart
Buddy Ross
John Getz
Sam Wood
Alan Tudyk
Ian McLellan Hunter
James DuMont
J. Parnell Thomas
Richard Portnow
Louis B. Mayer
Adewale Akinnuoye-Agbaje
Virgil Brooks
Stephen Root
Hymie King
Mattie Liptak
Chris Trumbo (Age 13-17)
Dean O'Gorman
Kirk Douglas
Garrett Hines
Andrew Hird
Christian Berkel
Otto Preminger
Dan Bakkedahl
Roy Brewer
Toby Nichols
Chris Trumbo (age 6-10) (as Tobias McDowell Nichols)
Dalton Trumbo
Himself (archive footage)
Laura Flannery
Party Goer
Madison Wolfe
Niki Trumbo (age 8-11)
Johnny Sneed
Robert Stripling
Rio Hackford
Reporter
Dane Rhodes
Reporter
Peter MacKenzie
Robert Kenny
John Neisler
Jury Foreman
Sean Bridgers
Jeff Krandall
Meghan Wolfe
Mitzi Trumbo (age 6-8)
Becca Nicole Preston
Mitzi Trumbo (age 9-12)
Mark Harelik
Edward 'Ed' Muhl
Jaclyn Bethany
Starlet (uncredited)
Kate Kuen
Ethel (uncredited)
Suzanne LaChasse
Showgirl (uncredited)
Rhonda Laizer
Trumbo Friend (uncredited)
Veronica Parks
Showgirl (uncredited)
Anne Speed
Juror (uncredited)