Dr. John Dolittle
Archer Dolittle
Dr. Mark Weller
Calloway
Dr. Gene 'Geno' Reiss
Lisa Dolittle
Dr. Fish
Maya Dolittle
Charisse Dolittle
Dr. Sam Litvack
Jeremy (as Erik Todd Dellums)
Diane
Mrs. Parkus
Intern
Patient at Hammersmith
Animal Control Officer
Receptionist
Beagle Woman (as Kellye Nakahara-Wallett)
Woman
Vet's Assistant
Busboy
Policeman
Security Guard (as Charles A. Branklyn)
Mounted Policeman
Mr. Galvin (the Principal)
Reverend
3-Year-Old John Dolittle
5-Year-Old John Dolittle
Reporter
Cop #1
Cop #2
Lucky (voice)
Jacob the Tiger (voice)
Rodney (voice)
Rat #1 (voice)
Rat #2 (voice)
Female Pigeon (voice)
Male Pigeon (voice)
Prologue Dog (voice)
Old Beagle (voice)
Drunk Monkey (voice)
Owl (voice)
Compulsive Dog (voice)
Goat (voice)
Pound Dog (voice)
Possum (voice)
Heavy Woman's Dog (voice)
German Shepherd (voice)
Skunk (voice)
Raccoon (voice)
'I Love You' Dog (voice)
Orangutan (voice)
Bettleheim the Cat (voice)
Baby Tiger (voice)
Pig (voice)
Penguin (voice)
Circus Clown (uncredited)
Blaine (uncredited)
Drunk Monkey (uncredited)
Jumping Boy (uncredited)
Veterinarian (uncredited)
Patient at Hammersmith (uncredited)