Jon and Garfield visit the United Kingdom, where a case of mistaken cat identity finds Garfield ruling over a castle. His reign is soon jeopardized by the nefarious Lord Dargis, who has designs on the estate. Garfield is back and this time Garfield and his canine sidekick Odie follows their owner, Jon Arbuckle, to England, the U.K. may never recover, as Garfield is mistaken for a look-alike, regal cat who has inherited a castle. Garfield savors the royal treatment afforded by his loyal four-legged subjects, but his reign is in jeopardy! The evil nefarious stubborn Lord Dargis is determined to do away with Garfield, so he can turn the castle into a resort. Garfield's bigger, better, more perfect world is soon turned upside down in this tale of two kitties.

Jon Arbuckle buys a second pet, a dog named Odie. However, Odie is then abducted and it is up to Jon's cat, Garfield, to find and rescue the canine. Garfield, the fat, lazy, lasagna lover, has everything a cat could want. But when Jon, in an effort to impress the Liz - the vet and an old high-school crush - adopts a dog named Odie and brings him home, Garfield gets the one thing he doesn't want. Competition. One night Odie runs away and gets dog-napped after Garfield locks him outside. Garfield, in an out of character move, goes to search for and rescue Odie with the help of a variety of animal friends along the way.