Jimmy Neutron / Alien Actress / Alien Woman (voice)

Carl Wheezer/Mr. Wheezer/Mrs. Wheezer/Test Pilot/Announcer (voice)

Sheen Estevez / Army Guard (voice)

Goddard (voice)

Cindy Vortex (voice)

Libby Folfax (voice)

Meldar Prime (voice)

April (voice)

Sr. Estevez (voice)

Gorlock #2 / Brain #1 (voice)

Judy Neutron / Mrs. Vortex (voice)

Brain #2 / Mayor Quadar (voice)

Hugh Neutron / Emergency System / Gen. Abercrombie (voice)

Meldar Prime (singing voice)

Sr. Estevez (voice)

Bolbi Stroganofsky / British Tourist (voice)

Sam / Corky Shumatsu (voice)

Vendanna (voice)