 Molly ShannonMrs. Baker | Mrs. Baker |
 Liam AikenOwen Baker | Owen Baker |
 Matthew BroderickHubble (voice) | Hubble (voice) |
 Donald FaisonWilson (voice) | Wilson (voice) |
 Cheech MarinThe Greater Dane's Henchman (voice) | The Greater Dane's Henchman (voice) |
 Brittany MurphyNelly (voice) | Nelly (voice) |
 Vanessa RedgraveThe Greater Dane (voice) | The Greater Dane (voice) |
 Carl ReinerShep (voice) | Shep (voice) |
 Delta BurkeBarbara Ann (voice) | Barbara Ann (voice) |
 Kevin NealonMr. Baker | Mr. Baker |
| HHunter ElliottFrankie | Frankie |
| MMikhael SpeidelFred | Fred |
 Brittany MoldowanConnie Fleming | Connie Fleming |
 George TouliatosMr. Leone | Mr. Leone |
 Patti AllanMs. Ryan | Ms. Ryan |
 Ben ImmanuelWilson's Dad (as Benjamin Ratner) | Wilson's Dad (as Benjamin Ratner) |
 Peter FlemmingWilson's Other Dad | Wilson's Other Dad |
 Paul VogtBob the Dog Catcher (as Paul C. Vogt) | Bob the Dog Catcher (as Paul C. Vogt) |
 Brenda CrichlowMrs. Fleming (as Brenda M. Crichlow) | Mrs. Fleming (as Brenda M. Crichlow) |
 D. Harlan CutshallMr. Fleming | Mr. Fleming |
| CChaka WhiteWoman at the Pound | Woman at the Pound |
 Nicola AndersonWoman at the Pound | Woman at the Pound |
 Ted FriendTV Anchorman | TV Anchorman |
 Susan BainHouse Bidder | House Bidder |
| BBannerBarbara Ann | Barbara Ann |
| WWillieShep | Shep |
 Mig MacarioAsian Dad (uncredited) | Asian Dad (uncredited) |
