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)

Elle Fanning
Grace (voice)

Dee Bradley Baker
Trashcan (voice)

Moisés Arias
Zane (voice)

Ryan Stiles
Mr. Moustachio / Burning Robot (voice)

Sofia Bowers
The Little Stinker (voice)