Debi Derryberry

James 'Jimmy' Isaac Neutron (voice)

Megan Cavanagh

Judy Neutron / VOX (voice)

Mark DeCarlo

Hugh Neutron / Pilot / Arena Guard (voice)

Jeffrey Garcia

Sheen Estevez (voice)

Patrick Stewart

King Goobot V (voice)

Martin Short

Ooblar (voice)

Frank Welker

Goddard / Poultra (voice)

Rob Paulsen

Carl Wheezer / Mr. and Mrs. Wheezer / Kid in Classroom (voice)

Carolyn Lawrence

Cindy Vortex (voice)

Crystal Scales

Libby Folfax (voice)

Candi Milo

Nick Dean / Britney / PJ (voice)

David L. Lander

Yokian Guard / Gus (voice)

Carlos Alazraqui

Mr. Estevez (voice)

Jim Cummings

Ultra Lord / Mission Control / General Bob (voice)