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)