Batman: The Long Halloween is a 2021 American two-part animated direct-to-video superhero film produced by Warner Bros. Animation and DC Entertainment, based on the DC Comics storyline of the same name. Part 1 is the 44th film, and Part 2 is the 45th film, of the DC Universe Animated Original Movies, with both parts serving as the third and fourth installments of the DC Animated Movie Universe's second phase, and the nineteenth and twentienth overall. The film is directed by Chris Palmer and stars the voices of Jensen Ackles, Josh Duhamel and Naya Rivera in her final film role before her death the year prior and is dedicated to her memory. In both parts of the film, Batman attempts to unravel the mystery of murders committed on holidays throughout the year, and uncover the true identity of the serial killer Holiday.

Part 1 was released on June 27, 2021, and Part 2 was released on July 27 the same year. A deluxe edition combining both films was released on September 20, 2022.