Fievel and his friend Tony Toponi find a map that they believe points to a treasure buried somewhere beneath Old New York, and the plucky rodent is determined to find it. However, what he discovers under the city is a tribe of Native American mice who were driven underground by prejudiced European immigrants.
| Actor | Role |
|---|---|
 Thomas DekkerFievel Mousekewitz (voice) | Fievel Mousekewitz (voice) |
 Lacey ChabertTanya Mousekewitz (voice) | Tanya Mousekewitz (voice) |
 Nehemiah PersoffPapa Mousekewitz (voice) | Papa Mousekewitz (voice) |
 Erica YohnMama Mousekewitz (voice) | Mama Mousekewitz (voice) |
 Dom DeLuiseTiger (voice) | Tiger (voice) |
| EElaine BilstadCholena (voice) | Cholena (voice) |
 Pat MusickTony Toponi (voice) | Tony Toponi (voice) |
 René AuberjonoisDithering (voice) | Dithering (voice) |
 David CarradineChief Wulisso (voice) | Chief Wulisso (voice) |
 Sherman HowardPolice Chief McBrusque (voice) | Police Chief McBrusque (voice) |
 Tony JayToplofty (voice) | Toplofty (voice) |
| RRichard KarronO'Bloat (voice) | O'Bloat (voice) |
 John KassirScuttlebutt (voice) | Scuttlebutt (voice) |
 Ron PerlmanGrasping (voice) | Grasping (voice) |
| JJean-Luc GalmicheVisqueux de Rat (voice) | Visqueux de Rat (voice) |