When advertising exec Phil Winslow (Lee Pace) gets an offer to head the account for a California-based dog-food company, he uproots his wife (($Judy Greer), three kids, and their beloved Great Dane, Marmaduke (voiced by Owen Wilson), from Kansas to the Sunshine State. Once there, the big canine befriends a group of mutts at the local dog park, but after a surfing competition brings Marmaduke celebrity, he turns his back on his new pals. Eventually, a disaster helps the oversized hound and Phil learn about the importance of family and friendship.