Nicolas Cage
Dr. Tenma (voice)
Madeline Carroll
Widget (voice)
Freddie Highmore
Astro Boy (voice)
Kristen Bell
Cora (voice)
Donald Sutherland
General Stone (voice)
Bill Nighy
Dr. Elefun (voice)
Eugene Levy
Orrin (voice)
Sterling Beaumon
Sludge (voice)
Nathan Lane
Ham Egg (voice)
Samuel L. Jackson
Zog (voice)
Charlize Theron
Narrator
David Alan Grier
Mr. Squirt / Math Cowboy / Boxer Robot
Alan Tudyk
Mr. Squeegee / Scrapheap Head / Stinger Two
Newell Alexander
General Heckler (voice)
Elle Fanning
Grace (voice)
Pilar Flynn
Cora's Mom (voice)
Dee Bradley Baker
Trashcan (voice)
Moisés Arias
Zane (voice)
Ryan Stiles
Mr. Moustachio/Burning Robot (voice)
Matt Lucas
Sparx (voice)
David Bowers
Mike the Fridge (voice)
Sofia Bowers
The Little Stinker (voice)
Nicole Fletcher
Oh No! Kid (voice)
Maryann Garger
Dr. Pigknuckle / Newscaster (voice)
Tiffany Hillkurtz
Bride to Be (voice)
David Feiss
Cowboy Robot (voice)
Nicholas Guest
French Waiter Robot (voice)
Max Burkholder
Billy (voice)
Victor Bonavida
Sam (voice)
Steve Alterman
Press Secretary (voice)
Rif Hutton
Metro City Sergeant (voice)
Madeleine Russell
Metro City Girl (voice)
Tony Matthews
Cora's Dad (voice)