Pete Davidson as Marmaduke (voice)

J.K. Simmons as Zeus (voice)

David Koechner as Phil Winslow (voice)

Mary Hart as EntertainMutt Tonight Host (voice)

Julie Nathanson as Dottie Winslow (voice)

Terri Douglas as Billy Winslow (voice)

Erin Fitzgerald as Barbara Winslow (voice)

Stephen Stanton as King Tut (voice)

Brian Hull as Guy Hilton (voice)

Sumalee Montano as Amy (voice)

Andrew Morgado as Henri / Phillipe (voice)

Chris Hackney as Announcer (voice)

Shelby Young as Shantrelle (voice)

Johnny Yong Bosch as Zhi (voice)

Nika Futterman as Juan Pedro (voice)

Melissa Disney as Javier (voice)

Fred Tatasciore as Vinnie (voice)

Jason Anthony as Ronnie (voice)

Vanessa Marshall as Phone Girl (voice)

Nickie Bryar as Derek (voice)

Joey Camen as Bee (voice)

Rene Mujica as Clown (voice)

Sean Rohani as Butcher (voice)

Joey D'Auria as Shar Pei (voice)

Cellin Gluck as Male Judge (voice)

Tania Gunadi as Cheerleader #1 (voice)

Rachelle Heger as Cheerleader #2 (voice)

Jason Pace as Capt. Jake S. Dean (voice)

Sarah Jean Pace as Chloe Laureno (voice)

Sabra May as Additional Voices (voice)

Rebecca Davis as Additional Voices (voice)

Brian T. Delaney as Additional Voices (voice)

Dave Fennoy as Additional Voices (voice)

André Sogliuzzo as Additional Voices (voice)