1. Warner Bros. offered Tim Burton the chance to direct Batman after the surprising financial success of Pee-wee's Big Adventure.
2. According to Tim Burton, he was heavily influenced by the dark tone of Alan Moore's Batman: The Killing Joke and Frank Miller's Batman: The Dark Knight Returns.
3. Actors who were originally considered for the role of Bruce Wayne/Batman included: Alec Baldwin, Tom Hanks, and Bill Murray.
4. After it was announced that Michael Keaton was cast as Bruce Wayne/Batman, Warner Bros. received over 50,000 angry letters from comic book fans who felt he was the wrong choice.
5. Adam West, who portrayed Batman in the 1960s TV series, was reportedly disappointed that he was not offered a chance to reprise the role — despite the fact that he was 60 years old at the time.
6. Jack Nicholson was always the first choice to play the Joker, but he initially declined the role. The part was then offered to Robin Williams, who accepted the role while the film was still in pre-production. But Nicholson then had a change of heart and Williams was released.
7. Other actors who were considered for the role of the Joker included: Tim Curry, Willem Dafoe, and David Bowie.
8. As part of his contract, Nicholson received a percentage of the film’s gross, and due to its massive box office he took home an estimated $60 million.
9. Sean Young was originally cast as Vicki Vale, but had to be replaced one week before shooting started after she fell off a horse and broke her collarbone.
10. After Sean Young dropped out of the role of Vicki Vale, Tim Burton wanted to cast Michelle Pfeiffer in her place. But Michael Keaton objected as he was dating Pfeiffer at the time and believed it would be too awkward.
11. Originally, the Joker was supposed to kill Vicki Vale toward the end of the film.
12. Dick Grayson/Robin was originally supposed to appear in a cameo, but the scene was cut as the filmmakers felt he was irrelevant to the plot. The video below is an animated storyboard sequence of how the scene would have appeared:
13. Before the character was written out of the script, Kiefer Sutherland was offered the role of Dick Grayson.
14. The Joker's real name in the film is Jack Napier. But the name was created for the film, as the Joker has never been given a real name in the comic books.
15. Batman wore boots designed by Nike.
16. Near the beginning of the film, when the character of Alexander Knox enters the pressroom, he is handed a cartoon sketch of a "bat man." The sketch was drawn and signed by Bob Kane, who is the original co-creator of Batman.
17. Prince was not the first choice to write and perform songs for the film; it was actually Michael Jackson.
Jackson had to turn down the opportunity due to his touring commitments.
18. Two separate soundtracks of the movie were released: One was the score by Danny Elfman and the other was an album of new songs Prince wrote just for the film.
19. Prince’s campy single "Batdance," from the Batman soundtrack, reached No. 1 on the Billboard Hot 100.
"Batdance" was a also a last-minute replacement for the original title track "Dance with the Devil," which Prince felt was too dark.