Scamp, the rambunctious son of Lady and Tramp, feels constricted by the rules of his loving but overprotective family. Eager to experience life as a "wild dog," he escapes his suburban home and joins a pack of stray dogs known as the Junkyard Dogs. The pack's leader, Buster, is skeptical but allows Scamp to prove himself. Along the way, Scamp befriends Angel, a street-smart stray with dreams of finding a family, who begins to show him the downsides of a life without structure.

As Scamp wrestles with his choice between the freedom of the streets and the safety of his home, tension builds between him and Buster. Scamp's dual loyalties are tested further when a scheme threatens the safety and unity of both his old and new friends. While Scamp's family searches for him, he must decide where he truly belongs and what kind of dog he wants to be.