Characters portrayed by Jack Nicholson in the Batman Universe
- Until 2016, with the release of Suicide Squad, Jack Nicholson was the only still-living actor to have played the Joker in an official live-action Batman film, as Cesar Romero, the Joker from the live action Batman TV show, died in 1994 and Heath Ledger, the Joker from The Dark Knight, died in 2008. In November 2014, Jared Leto was cast as the Joker for Suicide Squad.
- Nicholson is the only actor that used his real name for his character in the film.
- In 1975, Jack Nicholson co-starred with Danny DeVito in the drama film One Flew Over the Cuckoo's Nest, by Miloš Forman, both of whom would later have roles as villains in the Batman film franchise: Jack as The Joker in Batman and Danny as the Penguin in Batman Returns.
- In 1978, Jack Nicholson directed and co-starred with Danny DeVito and Tracey Walter in western film Goin' South.
- In 1987, he starred in the film The Witches of Eastwick with Michelle Pfeiffer, who would later star as Catwoman in Batman Returns.
- In 1990, he directed and co-starred with Tracey Walter in The Two Jakes.
- In 1992, Jack Nicholson was directed and co-starred with Danny DeVito in the biopic Hoffa, as Jimmy Hoffa.
- In 1994, Nicholson appeared with Michelle Pfeiffer again, this time shared the leading roles in horror film Wolf.
- In 1996, Nicholson starred in Mars Attacks!, another film directed by Tim Burton, with Danny DeVito in the cast. During casting, Burton had asked Nicholson what role he was interested in, to which Jack joking replied "All of them!". As a result, Burton elected to cast Nicholson in a dual role, one being sleazy real estate developer Art Land, and the other as the President of the United States.
- In 2007, Nicholson starred alongside Morgan Freeman (who portrays the role of Lucius Fox in The Dark Knight Trilogy) in The Bucket List.