Jimmy Neutron (voice)

Hugh Neutron (voice)

Judy / Vox 2000 (voice)

Carl / Mr. Wheezer / Butch (voice)

Sheen (voice) (as Jeff Garcia)

Cindy Vortex (voice)

Libby (voice)

Ms. Fowl (voice)

Sam / Louie (voice)

Nick (voice)

Nick's Singing Voice (as Jeff Gun)

Goddard / Twonkies (voice)

Themselves (voice)