Toby Tyler or Ten Weeks with a Circus (1960)

"Here comes...the HAPPIEST SHOW ON EARTH!"

Angered at stern Uncle Daniel, Toby Tyler runs away from his foster home to join the circus, where he soon befriends Mr. Stubbs, the frisky chimpanzee. However, the circus isn't all fun and games when the evil candy vendor, Harry Tupper, convinces Toby that his Aunt Olive and Uncle Daniel don't love him or want him back. Toby resigns himself to circus life, but when he finally realizes that Tupper lied to him, and that his aunt and uncle truly love him, Toby happily returns home once again.