Debi Derryberry as Jimmy Neutron (voice)

Tara Strong as Timmy Turner (voice)

Megan Cavanagh as Judy Neutron (voice)

Mark DeCarlo as Hugh Neutron (voice)

Rob Paulsen as Carl Wheezer / Announcer (voice)

Jeffrey Garcia as Sheen Estevez (voice)

Carolyn Lawrence as Cindy Vortex (voice)

Crystal Scales as Libby Folfax (voice)

Frank Welker as Goddard (voice)

Susanne Blakeslee as Wanda (voice)

Daran Norris as Cosmo / Dad / Jorgen Von Strangle (voice)

Grey DeLisle as Vicky / Principal Waxelplax (voice)

Carlos Alazraqui as Denzel Crocker (voice)

Dee Bradley Baker as Sanjay / Elmer / Fairy Agent #1 (voice)

Gary LeRoi Gray as A.J. (voice)

Faith Abrahams as Francis (voice)

Jim Ward as Tour Guide (voice)

Jason Marsden as Chester McBadbat (voice)