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)