Emma Stone Mazie (voice)

Judy Greer Debbie Winslow

Christopher Mintz-Plasse Giuseppe (voice)

Kiefer Sutherland Bosco (voice)

Owen Wilson Marmaduke (voice)

Sam Elliott Chupadogra (voice)

Ryan Devlin Deuce (voice)

Stacy Ferguson Jezebel (voice)

William H. Macy Don Twombly

Lee Pace Phil Winslow

Steve Coogan Raisin (voice)

George Lopez Carlos (voice)

Thomas F. Wilson (voice

Devon Werkheiser Drama Dog

David Walliams Anton Harrison

Carlos Ponce

Damon Wayans Jr. Thunder (voice)

Anjelah N. Johnson

Caroline Sunshine Barbara Winslow

Michael Teigen Gary

Finley Jacobsen Brian Winslow

Sydney Imbeau Small Little Girl

Glenn McCuen Bodie

Keith Dallas Emergency Road Worker

P.J. Prinsloo Fireman

Garvin Cross Tethered Fireman

Izaak Smith Basketball Captain

Milana Haines Sarah Winslow

Christopher Attadia Jock

Frank Topol Bosco's Owner

Charles Jarman Mover

Mandy Haines Sarah Winslow

Jennifer Louise La Voie Teacup poodle (voice)

John Daily Skater

Cameron Cowles Skater

Tyler Abiew Skater

Jason Bryden Man on Bench (uncredited)

Giovanni V. Giusti Beach Patron (uncredited)

Kirk McMeekan Fireman (uncredited)

Eduardo Noda Paramedic (uncredited)

David Stanfield Surf Announcer (uncredited)

Brad Williams Beagle (voice) (uncredited)