Ezra Miller
— Robert
Jeremy Allen White
— Dave
Emory Cohen
— Trevor
Michael Stuhlbarg
— Mr. Burke
Rosemarie DeWitt
— Miss Vogel
Addison Timlin
— Amy
David Costabile
— Mr. Anderson
Dariusz M. Uczkowski
— Peter
Gary Wilmes
— Mr. Virgil
Lee Wilkof
— Mr. Wiseman
Paul Sparks
— Detective Eclisse
Bill Raymond
— Mr. Williams
Alexandra Neil
— Gloria Talbert
Mark Zeisler
— Tom Talbert
Christopher McCann
— Mr. Ullman
Byrdie Bell
— Cherry Dee
Mary Michelson
— Talbert Twin
Carly Michelson
— Talbert Twin
Rebecca Boughton
— Broken Glass Girl 1
Anna Maliere
— Broken Glass Girl 2
Dani Baum
— Broken Glass Girl 3
Julian Branciforte
— Freshman Student
Marta Miller
— Robert's Mom (voice)
Annette Foisy
— Nurse
Paige Billings
— AV Class Girl
Tony Costagliola
— Senior Druggie
Cameron Ward
— Boys Dorm Head
Richard White
— Dave's Dad in Car
Christopher Brisson
— Security Guard
Mackenzie Deary
— Chapel Student