Debi Derryberry

Jimmy Neutron (voice)

Jeffrey Garcia

Sheen Estevez (voice)

Rob Paulsen

Carl Wheezer (voice)

James Sie

You Yee / Elderly Monk / Ninja (voice)

Peter Frampton

Hugh Neutron (singing voice)

Ming-Na Wen

Peggy Tsu (voice)

Tom Kane

Dean Cain (voice)

Wendie Malick

Beautiful Gorgeous (voice)

Christian Slater

Jet Fusion (voice)

Jim Meskimen

Quentin Smithee (voice)

Michael Clarke Duncan

Commander Baker (voice)

Ben Stein

Giggles the Clown (voice)

Mel Brooks

Santa Claus (voice)

Phyllis Diller

Granny Neutron (voice)

Neil Ross

Announcer (voice)

John Kassir

Seymour / Student #3 (voice)

Tress MacNeille

Annabelle / Aunt Kari / Great Aunt Amanda (voice)

Grey DeLisle

Elke (voice) · Mombot (voice)

Bill Farmer

Buford / Reporter (voice)

Corey Burton

Spamdini (voice) · Rayburn (voice)

Maurice LaMarche

Goddard Digital Voice (voice) · Zix / Ticket Taker (voice)

Michael Hagiwara

Japanese Announcer (voice)

Joe Lala

Mr. Estevez (voice)

Charlie Adler

Junkman (voice)

Jeff Bennett

Travoltron / Newscaster / Salesman (voice) · Travoltron/Barbarino (voice)

Jim Cummings

Captain Betty / Mayor (voice)

Billy West

Sam Melnick (voice) · TV Newscaster / Lucky Joe (voice)

Tom Kenny

Max / Wilderman / Mr. Moodini (voice) · WL3000 (voice)

Daran Norris

Nanobot #1 / Baby Quackers (voice)

Kath Soucie

Betty Quinlan (voice)

Jim Belushi

Coach Gruber (voice)

Kevin Michael Richardson

Tremendous Jackson (voice) · Tee (voice)

Candi Milo

Nick Dean / Germy (voice) · Nick Dean / Phantom #1 (voice)

Terry Wood

Singer (voice)

Paul Greenberg

Brobot (voice)

Megan Cavanagh

Judy Neutron / Lunch Lady (voice)

Mark DeCarlo

Hugh Neutron / Mr. Vortex (voice)

Phil LaMarr

Bolbi (voice)

Tim Curry

Professor Calamitous (voice)

Frank Welker

Goddard / Mr. Wuggles / Special Vocal Effects (voice) · Goddard / Phantom #4 / Special Vocal Effects (voice)

Andrea Martin

Ms. Fowl / Lady (voice) · Ms. Fowl (voice)

Crystal Scales

Libby Folfax / Chuck (voice)

Edie McClurg

Grandma Taters (voice)

Carolyn Lawrence

Cindy Vortex / Tina Sue (voice) · Cindy Vortex / Phantom #2 (voice)