The Yolkians have come to earth, but this time they seek out only peace and brotherhood with the people of Retroville. While Jimmy Neutron suspects the worst, everyone in town is ready to forgive and forget. This special serves as a direct sequel to the Jimmy Neutron movie.
| Actor | Role |
|---|---|
 Debi DerryberryJames Isaac 'Jimmy' Neutron / Nissa (voice) | James Isaac 'Jimmy' Neutron / Nissa (voice) |
 Megan CavanaghJudy Neutron / Vox (voice) | Judy Neutron / Vox (voice) |
 Mark DeCarloHugh Neutron / Yokian Waiter (voice) | Hugh Neutron / Yokian Waiter (voice) |
 Rob PaulsenCarl Wheezer / Principal Willoughby / Butch / Yokian (voice) | Carl Wheezer / Principal Willoughby / Butch / Yokian (voice) |
 Jeffrey GarciaSheen Estevez (voice) | Sheen Estevez (voice) |
 Carolyn LawrenceCindy Vortex (voice) | Cindy Vortex (voice) |
 Crystal ScalesLibby Fallfax (voice) | Libby Fallfax (voice) |
 Andrea MartinMiss Fowl (voice) | Miss Fowl (voice) |
 Candi MiloNick Dean / Woman #1 (voice) | Nick Dean / Woman #1 (voice) |
 Billy WestSam / Benny / Man #1 (voice) | Sam / Benny / Man #1 (voice) |
 S. Scott BullockKing Goobot / Yokian / Man #2 / Alarm (voice) | King Goobot / Yokian / Man #2 / Alarm (voice) |
 Paul GreenbergOoblar / Yokian Waiter (voice) | Ooblar / Yokian Waiter (voice) |
 Frank WelkerGoddard / Poultra (voice) | Goddard / Poultra (voice) |