Debi Derryberry
James Isaac 'Jimmy' Neutron (voice)
Christian Slater
Jet Fusion (voice)
Wendie Malick
Beautiful Gorgeous (voice)
Michael Clarke Duncan
Commander Baker (voice)
Tim Curry
Professor Calamitous (voice)
Dan Castellaneta
Professor Crank (voice)
Frank Welker
Goddard (voice)
Rob Paulsen
Carl Wheezer / Monk / Voice / Clam (voice)
Megan Cavanagh
Judy Neutron / Ms. Jingle Bells / Female Monk (voice)
Mark DeCarlo
Hugh Neutron (voice)
Jeffrey Garcia
Sheen Estevez (voice)
Andrea Martin
Ms. Fowl (voice)
Carolyn Lawrence
Cindy Vortex / Tina Sue (voice)
Crystal Scales
Libby Fallfax / Ike (voice)
Kath Soucie
Betty Quinlan (voice)
Corey Burton
Narrator / Head Monk
Ving Rhames
Chief (voice)