James Marsden
Role: Diggs (voice)
Nick Nolte
Role: Butch (voice)
Christina Applegate
Role: Catherine (voice)
Bette Midler
Role: Kitty Galore (voice)
Pascale Hutton
Role: Jackie
Katt Williams
Role: Seamus (voice)
Neil Patrick Harris
Role: Lou (voice)
Sean Hayes
Role: Mr. Tinkles (voice)
Wallace Shawn
Role: Calico (voice)
Roger Moore
Role: Tab Lazenby (voice)
Joe Pantoliano
Role: Peek (voice)
Michael Clarke Duncan
Role: Sam (voice)
Chris O'Donnell
Role: Shane
Fred Armisen
Role: Freidrich
Kiernan Shipka
Role: Little Girl
Paul Rodríguez
Role: Crazy Carlito (voice)
J.K. Simmons
Role: Gruff K-9 (voice)
Grey DeLisle
Role: Security Bulldog/Catherine's Niece/Cat Spy Analyst
E. G. Daily
Role: Scrumptious / Patches / Catherine's Niece (voice)
Phil LaMarr
Role: Paws / Cat Spy Analyst (voice)
Michael Beattie
Role: Angus MacDougall (voice)
Jeff Bennett
Role: Duncan MacDougall (voice)
Malcolm Stewart
Role: Captain Flemming
Dawn Chubai
Role: Reporter
Keith Dallas
Role: Coit Tower Guard
Len Morganti
Role: Rex (voice)
Betty Phillips
Role: Cat Lady
Christopher Lee Parson
Role: Hep Cat / Cat Spy Analyst (voice)
Bumper Robinson
Role: Cool Cat / Dog Killa / Cat Spy Analyst / Slim (voice)
Rick D. Wasserman
Role: Rocky (voice)
Roger L. Jackson
Role: Inmate Fat Cat (voice)
Bonnie Cahoon
Role: Dog HQ PA / Catherine's Niece (voice)
André Sogliuzzo
Role: Snobby K-9 (voice)
Carlos Alazraqui
Role: Cat Gunner / Cat Spy Analyst (voice)
Grey DeLisle
Role: Security Bulldog / Catherine's Niece / Cat Spy Analyst (voice)
Amitai Marmorstein
Role: Playland Worker
Robert Hewko
Role: Old Man
Mark Burgess
Role: Used Car Salesman
Sage Brocklebank
Role: Park Patron