Jimmy Neutron
Debi DerryberryJimmy Neutron (voice)
Jeffrey GarciaSheen Estevez (voice)
Rob PaulsenCarl Wheezer (voice)
Carolyn LawrenceCindy Vortex / Phantom #2 (voice), Cindy Vortex (voice), Cindy Vortex / Tina Sue (voice), Cindy Vortex / Yuri (voice)
Frank WelkerGoddard / Mr. Strych / Special Vocal Effects (voice), Special Vocal Effects (voice), Goddard / Mr. Wuggles / Special Vocal Effects (voice), Goddard / Tubbs / Special Vocal Effects (voice), Goddard / Special Vocal Effects (voice), Tubbs / Special Vocal Effects (voice), Goddard / Tubbs / Health Inspector / Special Vocal Effects (voice), Goddard / Wendel / Special Vocal Effects (voice), Goddard / Second Guard / Special Vocal Effects (voice), Goddard / Tubbs / Father / Special Vocal Effects (voice), Goddard / Phantom #4 / Special Vocal Effects (voice)
Mark DeCarloHugh Neutron / Jenson / Skeezicks (voice), Hugh Neutron / Man (voice), Hugh Neutron / Mr. Vortex (voice), Hugh Neutron / TV Announcer (voice), Hugh Neutron / Eddie / Newt / Gomer (voice), Hugh Neutron / Commercial Narrator (voice), Hugh Neutron / Octopus Man (voice), Hugh Neutron (voice), Hugh Neutron / General / Alien Man / Emergency System / Gleason Like Creature (voice), Hugh Neutron / Instructor (voice), Hugh Neutron / Flippy (voice), Hugh Neutron / Announcer (voice), Hugh Neutron / Clerk (voice)
Crystal ScalesLibby Folfax / Maggie (voice), Libby Folfax / Phantom #2 (voice), Libby Folfax / Chicks (voice), Libby Folfax / Student #2 (voice), Libby Folfax / Libby's Brother (voice), Libby Folfax / Ike (voice), Libby Folfax / Chuck (voice), Libby Folfax / Ozzie (voice), Libby Folfax / Libby's Mom (voice), Libby Folfax (voice)
Megan CavanaghMrs. Vortex / Vox (voice), Judy Neutron / Crowd Member #2 (voice), Judy Neutron / Vox (voice), Judy Neutron / Hilgo (voice), Judy Neutron / Mrs. Pizza Monster (voice), Judy Neutron / Lunch Lady (voice), Judy Neutron / Gretchen (voice), Judy Neutron / Woman (voice), Judy Neutron / Phantom #3 (voice), Martian #2 (voice), Judy Neutron / Mrs. Moran (voice), Judy Neutron / Old Lady Nusbaum (voice), Vox (voice), Judy Neutron / Masseuse / MaternoTron (voice), Judy Neutron / Mrs. Vortex / Aunt Suzy (voice), Judy Neutron / Mrs. Vortex (voice), Judy Neutron (voice), Judy Neutron / Girl (voice)
Andrea MartinMs. Fowl / Lady (voice), Ms. Fowl (voice)
Candi MiloNick Dean / Phantom #1 (voice), Nick Dean (voice), Nick Dean / Ignishka (voice), Nick Dean / Britney (voice), Nick Dean / Terry (voice), Nick Dean / Germy (voice), Britney (voice), Female Fish (voice), Nick Dean / Amber (voice)
Billy WestSam Melnick / Blix (voice), Sam Melnick / Corky Shimatzu / Kid (voice), Sam Melnick / Lance (voice), Corky Shimatzu / Larry Llama (voice), Sam Melnick (voice), Sam Melnick / Corky Shimatzu / Lars (voice), Blix (voice), Sam Melnick / Man (voice), Corky Shimatzu (voice), Sam Melnick / Pilot (voice), TV Newscaster / Lucky Joe (voice), Sam Melnick / Corky Shimatzu (voice), Sam Melnick / Lou / Reporter (voice)
Phil LaMarrBolbi / TV Announcer (voice), Bolbi (voice), Bolbi / Pitz / Teenager (voice), Bolbi / Toy Executive (voice)
Jim CummingsMayor / Dog (voice), Captain Betty / Mayor (voice), Martian #3 (voice), Popbot / Gortox / Goddard Speaking (voice), Ultra Lord (voice), Mayor (voice), Atila (voice)
Tom KennyMax / Wilderman / Mr. Moodini (voice), Copbot / Interviewer (voice), Nanobot #2 (voice), WL3000 (voice)
Jeff BennettTravoltron/Barbarino (voice), Travoltron / Newscaster / Salesman (voice), Dr. Moist / Announcer (voice), Positive Jimmy / Negative Jimmy / Macho Jimmy (voice)
Corey BurtonSpamdini (voice), Dr. Dark / Pizza Monster (voice), Head Monk (voice), Rayburn (voice)
Maurice LaMarcheZix / Ticket Taker (voice), Goddard Digital Voice (voice), Zix / Tee / Reporter (voice)
Kath SoucieBetty Quinlan (voice)
Tim CurryProfessor Calamitous (voice)
Grey DeLisleElke (voice), Sally (voice), Mombot (voice)
Joe LalaMr. Estevez (voice)
Daran NorrisNanobot #1 / Baby Quackers (voice), Nanobot #1 (voice)
Jim BelushiCoach Gruber (voice)
Kevin Michael RichardsonTee (voice), Tremendous Jackson (voice)
Phyllis DillerGranny Neutron (voice)
Michael HagiwaraMaster Hong / Ninja (voice), Japanese Announcer (voice)
Paul GreenbergBrobot / Man on TV (voice), Brobot (voice)
James SieYou Yee / Elderly Monk / Ninja (voice)
Peter FramptonHugh Neutron (singing voice)
Ming-Na WenPeggy Tsu (voice)
Tom KaneDean Cain (voice)
Wendie MalickBeautiful Gorgeous (voice)
Christian SlaterJet Fusion (voice)
Jim MeskimenQuentin Smithee (voice)
Michael Clarke DuncanCommander Baker (voice)
Ben SteinGiggles the Clown (voice)
Mel BrooksSanta Claus (voice)
Neil RossAnnouncer (voice)
John KassirSeymour / Student #3 (voice)
Tress MacNeilleAnnabelle / Aunt Kari / Great Aunt Amanda (voice)
Bill FarmerBuford / Reporter (voice)
Charlie AdlerJunkman (voice)- TTerry WoodSinger (voice)
Edie McClurgGrandma Taters (voice)