Debi Derryberry

Jimmy Neutron (voice)

Mark DeCarlo

Hugh Neutron (voice)

Megan Cavanagh

Judy / Vox 2000 (voice)

Rob Paulsen

Carl / Mr. Wheezer / Butch (voice)

Jeffrey Garcia

Sheen (voice) (as Jeff Garcia)

Carolyn Lawrence

Cindy Vortex (voice)

Crystal Scales

Libby (voice)

Andrea Martin

Ms. Fowl (voice)

Billy West

Sam / Louie (voice)

Candi Milo

Nick (voice)

Jeffrey M. Gunn

Nick's Singing Voice (as Jeff Gun)

Frank Welker

Goddard / Twonkies (voice)

Graystar

Themselves (voice)