Steve Coogan
Campbell Babbitt
Hilary Duff
Lucy Diamond
Olivia Thirlby
Tess Sullivan
Josh Peck
Jim Lement
Molly Shannon
Penelope Little
Brett Kelly
Blastoff! Chorus
Molly Price
Donna Arbetter
Max Hoffman
Fenster Itski
Sarah Lind
Peggy Popoladopolous
Laura Carswell
Lute Lement
Ingrid Nilson
Ann
Andrea Brooks
Sue
Andrew Wheeler
Principal Person
Gabrielle Rose
Mrs. Bridigan
Colleen Rennison
Sylvia
Aubrey Mozino
Blyth
Alexia Fast
Hannah (uncredited)
Kendra Waldman
Dusty Drake
Aaron Brooks
Ezra
Barry Greene
Sam Calalluci
Levi Sochet
Sam Calalluci (voice)
Katie Messina
Gina
Alana Husband
Angela
Barbara Greenbaum
Librarian
Brenna O'Brien
Diminutive Girl
Aiden Lane Robson
Gustave Person
David Allan Pearson
Grease Monkey
Jilena Cori
Mrs. Person
Patricia Drake
Mrs. Itski
Ashley Whillans
Blastoff! Chorus
Calum Worthy
Blastoff! Chorus
Advah Soudack
Blastoff! Chorus
Robin Eder-Warren
Blastoff! Chorus