Michael Angarano ... Will Stronghold
Kurt Russell ... Steve / The Commander
Kelly Preston ... Josie / Jetstream
Danielle Panabaker ... Layla
Christopher Wynne ... News Anchor (as Chris Wynne)
Kevin Heffernan ... Ron Wilson Bus Driver
Dee Jay Daniels ... Ethan (as Dee-Jay Daniels)
Kelly Vitz ... Magenta
Loren Berman ... Little Larry
Nicholas Braun ... Zach
Malika Haqq ... Penny (as Malika)
Khadijah Haqq ... Penny
Jake Sandvig ... Lash
Will Harris ... Speed
Mary Elizabeth Winstead ... Gwen / Royal Pain
Lynda Carter ... Principal Powers
Bruce Campbell ... Coach Boomer
Dustin Ingram ... Carbon Copy Kid
Steven Strait ... Warren Peace
Cloris Leachman ... Nurse Spex
Jim Rash ... Mr. Grayson / Stitches
David Foley ... Mr. Boy
Kevin McDonald ... Mr. Medulla
Amy Brown ... Twin
Kimmy Brown ... Evil Twin
Lucille Soong ... Cook
Zachry Rogers ... Young Commander
Tom Kenny ... Mr. Timmerman
Jill Talley ... Mrs. Timmerman
Patrick Warburton ... Royal Pain (voice)
Vakisha Coleman ... Student Sidekick (uncredited)
Sean Gordon ... Penny's Date (uncredited)
Hans Hernke ... Laser-Vision Boy (uncredited)
Katrina-Jovan Howard ... Student (uncredited)
Nicole Malgarini ... Freeze Girl (uncredited)
Jason Maxim ... Funky Prom Boy (uncredited)
Robert McMurrer ... Student (uncredited)
Jennifer Rhys ... Jill (uncredited)