Once Upon a Studio is a 2023 American live-action/animated crossover fantasy comedy short film produced by Walt Disney Animation Studios in celebration of the Walt Disney Company's centennial. Written and directed by Dan Abraham and Trent Correy, it was released by Walt Disney Pictures on October 16, 2023. In the film, Disney characters come to life from pictures hanging on the walls of the Roy E. Disney Animation Building following the end of a usual work day. The short's art style combines computer graphics, traditional animation and live-action, and features characters from the majority of the studio's works made up to that point, including all 62 feature films (including the then-forthcoming Wish), numerous short films, and some live-action Disney films featuring animation produced by the studio such as The Reluctant Dragon (1941), Mary Poppins (1964), Bedknobs and Broomsticks (1971), and Pete's Dragon (1977). The film was dedicated in memory of Burny Mattinson, the company's longest-serving employee, who made a cameo in the short and died eight months before its release.Once Upon a Studio premiered at the Annecy International Animation Film Festival on June 11, 2023, and had its first public showing in the United States on ABC's The Wonderful World of Disney on October 15, along with the linear television premiere of Encanto (2021). It was released on YouTube on December 24.