Gary Oldman as Herman Mankiewicz

Amanda Seyfried as Marion Davies

Lily Collins as Rita Alexander

Arliss Howard as Louis B. Mayer

Tom Pelphrey as Joseph Mankiewicz

Sam Troughton as John Houseman

Ferdinand Kingsley as Irving Thalberg

Tuppence Middleton as Sara Mankiewicz

Tom Burke as Orson Welles

Joseph Cross as Charles Lederer

Jamie McShane as Shelly Metcalf

Toby Leonard Moore as David O. Selznick

Monika Gossmann as Fräulein Frieda

Charles Dance as William Randolph Hearst

Jack Romano as Sid Perelman

Adam Shapiro as George S. Kaufman

John Churchill as Charles MacArthur

Jeff Harms as Ben Hecht

Derek Petropolis as Eddie Cantor

Sean Persaud as Tommy

Paul Fox as Joe Von Sternberg

Tom Simmons as Doctor

Nick Job as John Gilbert

Colin Ward as Older Man

Cooper Tomlinson as Younger Man

Julie Collis as Female Starlet

Arlo Mertz as Child Star

Craig Welzbacher as Rexford Tugwell

Jessie Cohen as Norma Shearer Thalberg

Desiree Louise as Irene Selznick

Amie Farrell as Mrs. Meyer

Ian Boyd as Slim

Jay Villwock as C.C.

Lou George as Ed the Gate Guard

John Lee Ames as Grady

Bill Nye as Upton Sinclair

Richmond Arquette as Heckler

David Lee Smith as Sinclair Supporter

Mario Di Donato as A Man's Voice (voice)

James Patrick Duffy as Another Man

Flo Lawrence as Maude Anderson

Sebastian Faure as Movie Star #1

Randy Davison as Maître D

Christian Prentice as Emcee

Leven Rambin as Eve - Shelly's Girlfriend

Rick Pasqualone as Singer

Gary Teitelbaum as Rabbi

Eden Wattez as Joanna Mankiewicz - Age 2

Roslyn Cohn as Elmma Wilson

Mark Fite as James Wilson

John Patrick Jordan as Best Original Screenplay Announcer

Ben Mankiewicz as Broadcaster, Academy Awards

Natalie Denise Sperl as Movie Star #2

Brian Michael Jones as Aide - Ben

Camille Montgomery as Starlet #1

Craig Robert Young as Charlie Chaplin

Paul Carafotes as Assistant Director

Anne Beyer as Female Party Goer

Joey Hagler as Male Party Goer

Sean Donnellan as Martin Butler

Stewart Skelton as News Reel I

Malachi Rivers as News Reel II

Keith Barber as News Reel III

Kaytlin Borgen as Mayer's Assistant

Madison West as Starlet #2

Elvy as Starlet #3

Ali Axelrad as Starlet #4

Adrienne Evans as Wife #1

Wylie Small as Wife #2

Dana Lyn Baron as Wife #3

Jaclyn Bethany as Typist (uncredited)

Cary Christopher as Young Joseph Mankiewicz (uncredited)

Michelle Twarowska as Joan Crawford (uncredited)

Kingston Vernes as Young Herman Mankiewicz (uncredited)

Jordan Matlock as Groundskeeper (uncredited)

Anthony Molinari as Hobo (uncredited)

Daniel Hoffman as MGM Child Star (uncredited)

Sebastian Twohey-Jacobs as Beach Goer (uncredited)