Eddie Murphy

Dr. John Dolittle

Ossie Davis

Archer Dolittle

Oliver Platt

Dr. Mark Weller

Peter Boyle

Calloway

Richard Schiff

Dr. Gene Reiss

Kristen Wilson

Lisa

Jeffrey Tambor

Dr. Fish

Kyla Pratt

Maya

Raven-Symoné

Charisse

Steven Gilborn

Dr. Litvack

June Christopher

Diane

Cherie Franklin

Mrs. Parkus

Norm Macdonald

Lucky (voice)

Chris Rock

Rodney (voice)

Albert Brooks

Tiger (voice)

Jenna Elfman

Owl (Voice)

Reni Santoni

Rat #1 (Voice)

John Leguizamo

Rat #2 (Voice)

Julie Kavner

Female Pigeon (voice)

Garry Shandling

Male Pigeon (voice)

Ellen DeGeneres

Prologue Dog (voice)

Paul Reubens

Raccoon (voice)

Eddie Frierson

Skunk (voice)

Phil Proctor

Drunk Monkey (Voice)

Gilbert Gottfried

Compulsive Dog (Voice)

Brian Doyle-Murray

Old Beagle (voice)

Doug Shamburger

Pound Dog (voice)

Jeff Doucette

Possum (voice)

Archie Hahn

Heavy Woman's Dog (voice)

Tom Towles

German Shepherd (voice)

Royce D. Applegate

'I Love You' Dog (voice)

Chad Einbinder

Bettleheim the Cat (voice)

Jonathan Lipnicki

Baby Tiger (voice)

Hamilton Camp

Pig (voice)

Kerrigan Mahan

Penguin (voice)

Mark Adair-Rios

Intern

Don Calfa

Patient at Hammersmith

Kellye Nakahara

Beagle Woman

Beth Grant

Woman

Yule Caise

Vet's Assistant

Charles Branklyn

Security Guard

Richard Penn

Mr. Galvin

Karl T. Wright

Reporter

Stan Sellers

Cop #1

Ming Lo

Cop #2

Paul Giamatti

Blaine (uncredited)

Benny Buettner

Circus Clown (uncredited)

Pruitt Taylor Vince

Patient at Hammersmith (uncredited)

Crystal the Monkey

Drunk Monkey (uncredited)

Arnold F. Turner

Animal Control Officer

Spencer Kayden

Circus Audience (uncredited)