- Josh Lucas as Batman/Bruce Wayne, his parents were killed when he was twelve years old. As an adult, he trained to become a crimefighter to ensure that no child in Gotham would endure what he had to. He entrusts his identity with Alfred Pennyworth and Lucius Fox, and works with Jim Gordon.
- Nathan Gamble portrays 12 year old Bruce Wayne.
- Paul Bettany as Joker, a robber who worked for Sal Maroni. To avoid being caught by Batman, he jumps into a vat of chemicals which disfigure him. He becomes the Joker and is the main antagonist.
- Eric Bana as Two-Face/Harvey Dent, Bruce Wayne's childhood friend, who is scarred by Sal Maroni and becomes the criminal, Two-Face. He is the secondary antagonist and partner of the Joker.
- Pierce Brosnan as Jim Gordon, an honest member of the police force who is partnered with Renee Montoya. He is a good friend to both Bruce Wayne and Batman, but doesn't know that they're the same person.
- 'Michael Moriarty 'as Alfred Pennyworth, Bruce Wayne's loyal butler and one of only two people who knows Batman's secret identity.
- Denzel Washington as Lucius Fox, the head of Wayne Enterprises and one of two men that knows Batman's identity.
- Rashida Jones as Renee Montoya, Gordon's partner on the force.
- Leslie Bibb as Vicki Vale, a reporter and Bruce Wayne's former girlfriend. They get back together after he saves her from Harvey Bullock.
- Vincent D'Onofrio as Harvey Bullock, a corrupt police officer on Maroni's payroll. He is the tertiary antagonist.
- Kevin Bacon as Salvatore Maroni, a major crime boss in Gotham.
- Sigourney Weaver as Leslie Thompkins, a close friend of Thomas Wayne's, and one of Batman's allies.
- Gerard Butler as Joe Chill, the man who murdered Thomas and Martha Wayne.
- Jennifer Anniston as Martha Wayne, Bruce Wayne's mother who was killed when he was 12 years old.
- Billy Crudup as Thomas Wayne, Bruce Wayne's father who was killed when he was 12 years old.
- Kevin James and Stephen Fry as Tweedledee and Tweedledum, Two-Face's henchmen and minor antagonists. Dee represents Two-Face's good side, while Dum represents his bad side.
- Jack Nicholson as Gillian B. Loeb, the corrupt police comissioner.
- Matthew Perry as Jeremiah Arkham, the sarcastic warden of Arkham Asylum.
- Doug Jones as Jonathan Crane, a respected psychologist that Bruce trains under when he is training to become Batman.
- Ray Stevenson as Kirk Langstrom, a kind psychologist at Arkham Asylum.
- Nicole Kidman as Sarah Essen, Harvey Dent's successor as District Attorney. It is hinted that she is attracted to Jim Gordon.
For his 12th birthday, Bruce Wayne goes to see the remake of the classic horror film, Clayface, along with his parents and his best friend, Harvey Dent. When they leave the theater, a mugger attempts to grab Martha's pearls, but Thomas breaks his hand. The mugger shoots him, and Martha reluctlantly gives the mugger her pearls. He says "Thanks", and then shoots Martha, anyway. Thomas tells Bruce to call Leslie Thompkins, just in case she can save them. Bruce doesn't know who Leslie is, or what her phone number is, so Thomas begins to tell him her number. Unfortuneately, he dies before he can finish saying the number. Bruce starts screaming "Nooooo!". Harvey tries to comfort Bruce, but Bruce punches him in the face. He immediately apologizes, and Harvey forgives him. They run back to Wayne Manor, and Bruce cries in Alfred's arms. Harvey calls his mom to tell her what happened, and to come pick him up. Unfortunately, his abusive dad, James, picks him up. He makes Harvey promise not to hang out with Brce Wayne anymore, and beats Harvey up when he says "No, Bruce is my best friend."
15 years later: Bruce Wayne finds that Joe Chill has just gotten out of prison, and formulates plans to kill him. His girlfriend, Vicki Vale, decides to dump him because she thinks that's morally wrong. Bruce discovers that Joe has already been killed, and instead decides to avenge his parents' deaths by training as a crimefighter.
First, Bruce studies criminal psychology under Jonathan Crane, and then leaves Gotham for 10 years to train as a crimefighter. more to come
Bruce has finished his training and comes home to Gotham City, where most people thought he was dead. On the Wayne Manor grounds, a sinkhole forms, and Bruce falls inside. Bats swarm out, and Bruce decides to use them as inspiration for his crimefighting persona. He becomes Batman, and confides his identity to only two people, Alfred and Lucius Fox (who provides Batman with gadgets.). On his first night on patrol, Batman learns about a raid on a chemical plant. Batman intercepts the robber, and the robber jumps into a vat of chemicals to avoid being caught. He later crawls out of a sewer pipe only to find Batman, Jim Gordon, and Renee Montoya (who is pointing at the robber with a gun) waiting for him. The robber agrees to help set up a sting against Sal Maroni, who set up the robbery and is the man controlling most of Gotham's criminal underworld (making him a wanted man in Gotham), so that his sentence will be shortened. The sting is successful and Sal is arrested. In court, Sal gets angry at the robber for betraying him, and attempts to throw acid in his face (not knowing of his previous disfigurement because of a mask the robber was wearing). The robber ducks and the acid hits the judge, who is Bruce's old friend, Harvey Dent (it only disfigures one side of his face because he had turned his head to speak with someone). It also melts one side of Dent's silver dollar. Dent then flees the courtroom with his coin. In the ensuing chaos, the robber escapes and Sal Maroni is accidentally shot.
The next day, Harvey is walking in in alley with his face covered. He bumps into someone who reveals himself to be the robber. Dent is mad at him because if he hadn't ducked, he himself wouldn't have gotten scarred. The robber takes of his mask and reveals his previous disfigurement to Dent. He says that the two of them have a couple of things in common. They've both been scarred, and they both have a vendetta against Sal Maroni. The robber (now calling himself Joker) proposes the idea that the two of them team up. He starts to share his plan with Harvey, but is interrupted by him. Harvey flips his coin, and it lands good side up, so he agrees to team up with Joker. The Joker then shares his plan with Harvey. He says " In one week... more to come
The film recieved great critical reception. It recieved an 89% on Rotten Tomatoes, and a weighted average score of 8.5/10 on Metacritic. Roger Ebert lauded Josh Lucas's performance as Bruce Wayne/Batman, saying that "much like Michael Keaton, he delivered an unexpectedly great performance as the Dark Knight." IGN praised Paul Bettany's performance, stating that "He does Heath Ledger justice in his performance as the Joker.