Bryan Cranston as Dalton Trumbo

Diane Lane as Cleo Trumbo

Helen Mirren as Hedda Hopper

Elle Fanning as Nikola Trumbo

Louis C.K. as Arlen Hird

John Goodman as Frank King

Michael Stuhlbarg as Edward G. Robinson

David James Elliott as John Wayne

Roger Bart as Buddy Ross

Mark Harelik as Ed Muhl

John Getz as Sam Wood

Alan Tudyk as Ian McLellan Hunter

James DuMont as J. Parnell Thomas

Richard Portnow as Louis B. Mayer

Adewale Akinnuoye-Agbaje as Virgil Brooks

Stephen Root as Hymie King

Mattie Liptak as Chris Trumbo (Age 13-17)

Dean O'Gorman as Kirk Douglas

Garrett Hines as Andrew Hird

Christian Berkel as Otto Preminger

Dan Bakkedahl as Roy Brewer

Toby Nichols as Chris Trumbo (age 6-10) (as Tobias McDowell Nichols)

Dalton Trumbo as Himself (archive footage)

Laura Flannery as Party Goer

Madison Wolfe as Niki Trumbo (age 8-11)

Johnny Sneed as Robert Stripling

Rio Hackford as Reporter

Dane Rhodes as Reporter

Peter MacKenzie as Robert Kenny

John Neisler as Jury Foreman

Sean Bridgers as Jeff Krandall

Meghan Wolfe as Mitzi Trumbo (age 6-8)

Becca Nicole Preston as Mitzi Trumbo (age 9-12)

Mark Harelik as Edward 'Ed' Muhl

Jaclyn Bethany as Starlet (uncredited)

Kate Kuen as Ethel (uncredited)

Suzanne LaChasse as Showgirl (uncredited)

Rhonda Laizer as Trumbo Friend (uncredited)

Veronica Parks as Showgirl (uncredited)

Anne Speed as Juror (uncredited)