Max Records
Max
Catherine Keener
Mom
James Gandolfini
Carol (voice)
Lauren Ambrose
KW (voice)
Catherine O'Hara
Judith (voice)
Forest Whitaker
Ira (voice)
Chris Cooper
Douglas (voice)
Paul Dano
Alexander (voice)
Spike Jonze
Bob (voice) / Terry (voice)
Pepita Emmerichs
Claire
Mark Ruffalo
The Boyfriend
Max Pfeifer
Claire's Friend
Madeleine Greaves
Claire's Friend
Joshua Jay
Claire's Friend
Ryan Corr
Claire's Friend
Steve Mouzakis
Teacher
Michael Berry Jr.
The Bull (voice)
Vincent Crowley
Carol Suit Performer
Sonny Gerasimowicz
Alexander Suit Performer
Nick Farnell
Judith Suit Performer
Sam Longley
Ira Suit Performer
Angus Sampson
The Bull Suit Performer
Mark McCracken
The Bull Additional Suit Performer
John Leary
Douglas Suit Performer
Alice Parkinson
KW Suit Performer
Garon Michael
KW Additional Suit Performer
James Epinfaniou
Additional Max Performer
Joshua Evans
Additional Max Performer
Tess Grimshaw Lloyd
Additional Max Performer
Lucas Haynes
Additional Max Performer
Nathan Veal
Additional Max Performer
Kalia Prescott
Max's Classmate (uncredited)