Hey A.J.! is an American animated children's television series created by Martellus Bennett, Michael Hodges, and Phineas and Ferb’s co-creator Jeff "Swampy" Marsh, based on the book series of the same name by Bennett. The show revolves around a girl with a sprawling imagination named A.J., as she goes on imaginative adventures with her stuffed bunny, Theo, and her friends and family. It premiered on Disney Jr. on January 13, 2026, and was released on Disney+ the following day.