Posthumous films and awards
Ledger's death affected the marketing campaign for Christopher Nolan's The Dark Knight (2008) and also both the production and marketing of Terry Gilliam's film The Imaginarium of Doctor Parnassus, with both directors intending to celebrate and pay tribute to his work in these films. Although Gilliam temporarily suspended production on the latter film, he expressed determination to "salvage" it, perhaps using computer-generated imagery (CGI), and dedicated it to Ledger. In February 2008, as a "memorial tribute to the man many have called one of the best actors of his generation," Johnny Depp, Jude Law, and Colin Farrell signed on to take over Ledger's role, becoming multiple incarnations of his character, Tony, transformed in this "magical re-telling of the Faust story". The three actors donated their fees for the film to Ledger's and Williams's daughter.
Speaking of editing The Dark Knight, on which Ledger had completed his work in October 2007, Nolan recalled, "It was tremendously emotional, right when he passed, having to go back in and look at him every day. ... But the truth is, I feel very lucky to have something productive to do, to have a performance that he was very, very proud of, and that he had entrusted to me to finish." All of Ledger's scenes appear as he completed them in the filming; in editing the film, Nolan added no "digital effects" to alter Ledger's actual performance posthumously. Nolan dedicated the film in part to Ledger's memory, as well as to the memory of technician Conway Wickliffe, who was killed during a car accident while preparing one of the film's stunts.
Released in July 2008, The Dark Knight broke several box office records and received both popular and critical accolades, especially with regard to Ledger's performance as the Joker. Even film critic David Denby, who does not praise the film overall in his pre-release review in The New Yorker, evaluates Ledger's work highly, describing his performance as both "sinister and frightening" and Ledger as "mesmerizing in every scene", concluding: "His performance is a heroic, unsettling final act: this young actor looked into the abyss." Attempting to dispel widespread speculations that Ledger's performance as the Joker had in any way led to his death (as Denby and others suggest), Ledger's co-star and friend Christian Bale, who played opposite him as Batman, has stressed that, as an actor, Ledger greatly enjoyed meeting the challenges of creating that role, an experience that Ledger himself described as "the most fun I've ever had, or probably ever will have, playing a character". Terry Gilliam also refuted the claims that playing the Joker made him crazy, calling it "absolute nonsense" and going on to say, "Heath was so solid. His feet were on the ground and he was the least neurotic person I've ever met."
Ledger received numerous awards for his Joker role in The Dark Knight. On 10 November 2008, he was nominated for two People's Choice Awards related to his work on the film, "Best Ensemble Cast" and "Best Onscreen Match-Up" (shared with Christian Bale), and Ledger won an award for "Match-Up" in the ceremony aired live on CBS in January 2009.
On 11 December 2008, it was announced that Ledger had been nominated for a Golden Globe Award for Best Supporting Actor – Motion Picture for his performance as the Joker in The Dark Knight; he subsequently won the award at the 66th Golden Globe Awards ceremony telecast on NBC on 11 January 2009, with Dark Knight director Christopher Nolan accepting on his behalf.
Film critics, co-stars Maggie Gyllenhaal and Michael Caine and many of Ledger's peers in the film community joined Bale in calling for and predicting a nomination for the 2008 Academy Award for Best Supporting Actor in recognition of Ledger's achievement in The Dark Knight. Ledger's subsequent nomination was announced on 22 January 2009, the anniversary of his death.
Ledger went on to win the Academy Award for Best Supporting Actor, becoming the second person to win a posthumous Academy Award for acting (after fellow Australian actor Peter Finch, who won for 1976's Network), as well as the first comic-book movie actor to win an Oscar for their acting. Ledger's family attended the ceremony on 22 February 2009, with his parents and sister accepting the award onstage on his behalf. Following talks with the Ledger family in Australia, the academy determined that Ledger's daughter, Matilda Rose, would own the award. However, due to Matilda's age, she would not gain full ownership of the statuette until her eighteenth birthday in 2023. Her mother, Michelle Williams, would hold the statuette in trust for Matilda until that time.
On 4 April 2017, a trailer was released for the documentary I Am Heath Ledger, which was released on 3 May 2017. It features archival footage of Ledger and interviews.