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)

Mike Gasaway