as James 'Jimmy' Isaac Neutron (voice)

as Judy Neutron (voice) / VOX (voice)

as Hugh Neutron (voice)

as Sheen Estevez (voice)

as King Goobot V (voice)

as Ooblar (voice)

as Goddard (voice) / Poultra (voice)

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

as Cindy Vortex (voice)

as Libby Folfax (voice)

as Nick Dean (voice) / Britney (voice) / PJ (voice)

as Yokian Guard (voice) / Gus (voice)

as Mr. Estevez (voice)

as Ultra Lord (voice) / Mission Control (voice) / General Bob (voice)

as Bobby (voice) / Kid (voice) / Control Yokian (voice)

as Zachary (voice) / Reporter (voice) / Angie (voice) / Libby's Mom (voice)

as Ms. Winfred Fowl (voice)

as Bobby's Twin Brother (voice) / Butch (voice) / Jailbreak Cop (voice) / Old Man Johnson (voice) / Robobarber (voice) / Flurp Announcer (voice) / Yokian Officer (voice) / Anchor Boy (voice) / Guard (voice)

as Yokian Newscaster #1 / Yokian Newscaster #1 (voice)

as Yokian Newscaster #2 (voice)

as Norad Officer (voice)

as Hostess (voice)

as Octapuke Kid / Guard / Bennie (voice)

as Guard (voice)

as Yokian Incubator Operator (voice)