In the 2008 film "The Dark Knight", which actor plays the Joker?

In the 2008 film "The Dark Knight," Heath Ledger plays the Joker.

Ledger’s Joker is the principal antagonist of Christopher Nolan’s second Batman film, a criminal mastermind who seeks to create chaos in Gotham City rather than pursue ordinary power or wealth. His deliberately unexplained identity and history make him especially distinct from many earlier versions of the character.

Ledger’s casting initially surprised some viewers because he was known for dramatic roles rather than comic-book villains. He based the performance on influences including The Killing Joke, A Clockwork Orange, punk culture, and the paintings of Francis Bacon. The Joker’s scars and smeared makeup also differ from comic-book versions in which the character’s skin is chemically bleached.

Ledger died in January 2008, before the film’s release, and received the Academy Award for Best Supporting Actor posthumously. Joaquin Phoenix and Jack Nicholson also played the Joker in other films, but neither portrays him in The Dark Knight.