Those italicized are Droopy, Master Detective characters (except the last heading). Boldface means that the characters appeared both in Tom & Jerry Kids & Droopy, Master Detective.
Principal Voice Actors[]
- Charlie Adler as Dripple, Urfo's Mother, Lightning Bolt, Rap Rat, Crazy Legs, Screwball Squirrel, Mumfrey the Butler, Crazy Legs
- William Callaway as Slowpoke Antonio, Rumpley
- Patrick Fraley as Kyle, The Yolker, Zebra, Tyrone the Tiny
- Teresa Ganzel as Miss Vavoom, Cindy-Lou, Lieutenant Lucy, White Tabby, Misty Mouse
- Dick Gautier as Spike
- Phil Hartman as Calaboose Cal, Hot Dog Vendor from "Pound Hound", Inspector De Paws
- Don Messick as Droopy, Bat Mouse, Narrator ("Scourge of the Sky")
- Frank Welker as Tom Cat, Jerry Mouse, McWolf, Wild Mouse, Caveman from "Prehistoric Pals", Bat Cat, Urfo, Ants, Zapmen, Urfo-Catcher, Fido's Cat Self, Orphan Kitten, Commander ("Scourge of the Sky"), Police Officer ("Eradicator Droopy"), Moncy, Salesmouse, Martian Mouse, Museum Manager, Stinky Jr., Dweeble, Mouse Chase Students (male), Jester ("When Knights Were Cold"), Narrator ("Wild Mouse II"), Grunch the Caveman
- Patric Zimmerman as Tyke
Voice Actors Introduced in Season 1[]
- Sorrell Booke as Mandible Mangler, Wrestling Announcer
- Scott Bullock
- Arthur Burghardt
- Hamilton Camp
- Townsend Coleman
- Danny Cooksey
- Peter Cullen as Dogcatcher ("The Little Urfulls"), Bazooka
- Brian Cummings as Clyde, El Gordo ("Zorrito"), Mugger ("Flippin' Fido")
- Joanie Gerber
- Arte Johnson as Shadowman
- Paul Kreppel
- Allan Lurie
- Tress MacNeille as Cleocatra
- Kenneth Mars
- Edie McClurg as Chino's Mother
- Gary Owens as Narrator ("Hard to Swallow," "Wild World of Bowling")
- Rob Paulsen as Edna Evergreen, Crummy McMummy, Prime Minister Luck-Nuck, Oliver J. Tudball, Kevin Castner, unnamed Woody Allen lookalike director from "Stunt Cat"
- Clive Revill
- Neil Ross
- Kath Soucie as Sugar-Belle, Snookie, Babysitter, Toliver
- Barbara Stuart
Voice Actors introduced in Season 2[]
- Brandon Adams as Buzz
- Joe Alaskey
- Rene Auberjonois as Hungry Pierre
- Gregg Berger
- Nicole Brown
- Greg Burson
- Jim Cummings as Redbeard, P.T. Pompbottom, Dwayne the Dragon, Tundo the Elephant, Mugger ("Disc Temper"), The Bloodfather, Babyman, Frankenator, McWolf's horse, Pierre Le Poulet, the Raj
- Tim Curry as the Sheriff of Rottingham, Mr. Banker of Ye Olde Fog Bank ("Droop and Deliver")
- Brad Garrett as Sir Butch-a-Lot ("Good Knight Droopy")
- Kathy Garver
- Jerry Houser as Dragon, Urfo ("The Little Thinker" version)
- Tony Jay as Narrator ("Jerry Hood and His Merry Meeces"), King
- Vicki Juditz
- Kip King
- David Lander as Bernie the Bird, Kitten Chase Students (male)
- Chuck McCann as Fido, King of the Sea, Babyman's Henchman
- Brian Mitchell
- Bibi Osterwald as Tera Boom-Boom
- Henry Polic II
- Kimmy Robertson
- Sally Struthers as Jerry's Mom
- Lee Wilkof
- Joanne Worley
Voice Actors introduced in Seasons 3 & 4[]
- Patricia Alice Albrecht
- Lewis Arquette
- Michael Bell as Roqueford Le Poulet, Ding Gator
- Susan Blu as Percy, Auntie Snoople
- Charlie Brill
- Nancy Cartwright as Mary-Lou
- Marsha Clark
- Selette Cole
- Bud Cort
- Jesse Corti
- Jennifer Darling as Fifi
- Mari Devon
- Nancy Dessault
- Maggie Egan
- June Foray as Groteska ("Doom Manor")
- Barry Gordon
- Archie Hahn
- Pamela Hayden
- George Hearn
- Dana Hill as Tim
- Zale Kessler
- Maurice LaMarche as Thundergut the Super Squirrel
- Sherry Lynn
- Diane Michelle
- Alan Oppenheimer
- Patricia Parris as Van Upshot
- Pat Pinney
- Tony Pope
- Hal Rayle
- Bob Ridgely as Sheriff Potgut
- Stuart Robinson
- Roger Rose as Johnsy Megabucks
- Sonnie Schell
- Susan Silo
- Hal Smith
- Marcelo Tubert
- Janet Waldo as Wild Mouse's Mother
- B.J. Ward as The Mistress of Baskerville Manor
- Jimmy Weldon
- Jane Wiedlin
- April Winchell as Mermaid ("High Seas Hijinks")
Voice Actors exclusively on Droopy Master Detective[]
- Sheryl Bernstein
- Charity James
- Nick Jameson
- Nancy Linari as Zombina
- Sarah Silverman as Melody WOOO-WOOO Stardust
- Michael Stanton
- Paul Winchell as Rumpley's dad
- Kris Zimmerman
- Valery Pappas