Joker: Folie à Deux is an upcoming American musical psychological thriller film slated to be a sequel to the 2019 film Joker. Joaquin Phoenix reprises his role as the DC Comics character the Joker, and Lady Gaga plays Harley Quinn. Zazie Beetz also reprises her role from the first film. The film is directed by Todd Phillips, who also co-wrote the screenplay with Scott Silver. It is produced by Warner Bros. Pictures and DC Studios in association with Village Roadshow Pictures, Bron Creative and Joint Effort.

Joker was intended to be a standalone film, but Warner Bros. intended for it to launch DC Black. Phillips said in August 2019 that he would be interested in making a sequel, but later clarified Joker was not set up to have one. Phoenix hinted a possibility to reprise his role in October. A sequel officially entered development in June 2022, with Gaga and Beetz joining later that year. Principal photography took place in Los Angeles, New York City, and Belleville, New Jersey, from December 2022 to April 2023.

Joker: Folie à Deux is scheduled to be released in the United States on October 4, 2024, by Warner Bros. Pictures.