Alex Pettyfer as Kyle Kingson

Vanessa Hudgens as Lindy Taylor

Mary-Kate Olsen as Kendra Hilferty

LisaGay Hamilton as Zola Davies

Neil Patrick Harris as Will Fratalli

Dakota Johnson as Sloan Hagen

Erik Knudsen as Trey Madison

Peter Krause as Rob Kingson

David Francis as Dr. Davis

Gio Perez as Victor Barrel

Karl Graboshas as Male Teacher

Jonathan Dubsky as Student at Green Party

Rhiannon Moller-Trotter as Halloween Partygoer

Miguel Mendoza as Victor's Brother

Roc LaFortune as Lindy's Father

Steve Godin as Junkie

Justin Bradley as Student

Julie Dretzin as Rob's Assistant

Mia Doran as Student (uncredited)

Devin Mroz as Student (uncredited)

Cristina Franco as Shopper (uncredited)