Astro Boy

Freddie Highmore

Astro / Toby (voice)

Kristen Bell

Cora (voice)

Nathan Lane

Hamegg (voice)

Eugene Levy

Orrin (voice)

Matt Lucas

Sparx (voice)

Bill Nighy

Dr. Elefun / Robotsky (voice)

Donald Sutherland

President Stone (voice)

Charlize Theron

"Our Friends" Narrator (voice)

Nicolas Cage

Dr. Tenma (voice)

Madeline Carroll

Widget (voice)

Sterling Beaumon

Sludge (voice)

Samuel L. Jackson

Zog (voice)

David Alan Grier

Mr. Squirt / Math Cowboy / Boxer Robot (voice)

Alan Tudyk

Mr. Squeegee / Scrapheap Head / Stinger Two (voice)

Newell Alexander

General Heckler (voice)