Batman: Gotham by Gaslight is a 2018 American adult animated superhero film produced by Warner Bros. Animation and distributed by Warner Bros. Home Entertainment, featuring an alternate version of the DC Comics character Batman. It is the 31st film of the DC Universe Animated Original Movies. It is directed and produced by Sam Liu and written by James Krieg, loosely based on the standalone graphic novel of the same name by Brian Augustyn and Mike Mignola.

The film was released for a world premiere screening at the Newseum in Washington, D.C. during the "DC in D.C." event on January 12, 2018 and then for digital download on January 23, 2018 before coming out on DVD and Blu-ray on February 6. Batman: Gotham by Gaslight was the last film to be released in Benjamin Melniker's lifetime, a longtime DC film producer who died a month later at the age of 104.