- Gotham City Police Department
- Murray Franklin (First appearance; dies)
- Wayne Enterprises
- Thomas Wayne (First appearance; dies)
- Debra Kane (First appearance)
- Alfred Pennyworth (First appearance)
- Benjamin Stoner (First appearance) (Flashback only)
- Bruce Wayne (First appearance)
- Carl (First appearance)
- Clown Protesters
- Joe Chill (First appearance) (Unnamed)
- Gary (First appearance)
- Gene Ufland (First appearance)
- GiGi Dumond (First appearance)
- Hoyt Vaughn (First appearance)
- Martha Wayne (First appearance; dies)
- Randall (First appearance; dies)
- Gotham City
Arthur, while doing his routine dressed as a clown, is harassed by grade-schoolers who steal his sign. They lead him to a blind alley-way, where they ambush him and leave him beaten on the floor. He goes up to his apartment to take care of his mother. She states that she is waiting for a letter from Thomas Wayne.
The next day, Arthur goes to his workplace and Randall gives him a gun. His boss then insults him and accuses him of stealing the business' sign. While in his apartment's elevator, he meets Sophie, his neighbor.
While on the train after a failed job, three college youths approach Arthur to mock him; they knock him on the floor and start to kick and beat him. Arthur shoots two of the youths dead while one flees. Arthur shoots him in the back, leaving all three youths dead.
The next day, the train murders are broadcasted on the news. Thomas Wayne claims the murderer to be a coward and those who can't get their life together are "clowns." Arthur is then seen speaking to his therapist. She informs him that the meeting would be the last since the city cut funding to support it. This causes Arthur to no longer have access to his medication.
While walking in Gotham, he sees support of the killer clown from strangers, saying he represents the poor and forgotten. He goes back to his apartment and his mother asks Arthur to mail out some letters written by her to Thomas Wayne. Arthur opens the letters, only to discover that his mother is claiming him to be the illegitimate child of Thomas.
Arthur goes to Wayne Manor where he talks to Bruce and harasses Alfred. His mother is sent to the hospital and Arthur is suspected by police. Arthur views a taping of the Murray Franklin show, where they insult his stand-up.
Later, Arthur talks to Thomas, where Thomas calls his mother crazy and says he's not his son. Arthur goes to Arkham Asylum to get his mother's records. He finds out that he is adopted and she is lying. Arthur goes back to the hospital and kills her. Afterwards, he gets a call to be on the Franklin Show. Gary and Randall go to check up on him, only for him to kill the latter.
Arthur later runs from the police as he heads to the show. While on the show, Arthur assumes the name "Joker" and confesses to the train murders. Joker then kills Murray and is arrested. Riots break outside and the hit the police car, freeing Joker. He embraces them.
Joker is then seen in a mental hospital speaking to a new therapist. The movie ends with him in bloody shoes being chased, insinuating that he killed her.
- Joaquin Phoenix - Arthur Fleck/Joker
- Robert De Niro - Murray Franklin
- Zazie Beetz - Sophie Dumond
- Frances Conroy - Penny Fleck
- Brett Cullen - Thomas Wayne
- Douglas Hodge - Alfred Pennyworth
- Dante Pereira-Olson - Bruce Wayne
- Marc Maron - Gene Ufland
- Carrie Louise Putrello - Martha Wayne
- A number of scenes were cut from the final version of the film:
- One of the deleted scenes revolved around Arthur visiting the Gotham Cemetery, presumably attending the funeral for his mother. A shot from this scene remained intact in the final trailer released in August.
- After Arthur leaves the Ha-Ha Talent Agency, an additional scene depicts an argument between him and Randall in front of a giant Amusement Mile graffiti.
- As seen in multiple teaser trailers, there was originally a scene in which Arthur is thrown out of the cinema by security guards and seen rolling down the stairs.
- It is mentioned in the news that giant super rats suddenly started to pop up in Gotham City, which make a short cameo appearance at Crime Alley near the end of the movie. This is a possible nod to the Batman Villain known as the Ratcatcher.
- The work badge of Arthur's social worker reveals her name to be Debra Kane. The character of social worker Debra Kane was originally created by writer Andrew Vachss for the novel Batman: The Ultimate Evil. Of course, the name is also a tribute to Batman co-creator Bob Kane.
- The logo for Live! With Murray Franklin is written in the same font as the Batman: The Animated Series logo.
- The colors of Arthur's Joker suit match the basic colors used for the curtains at Murray Franklin's talk show.
- The concept of the Clown Protesters who worship the Joker while wearing clown masks originates from Detective Comics (Volume 2) #5 by Tony S. Daniel, which in turn was inspired by the Jokerz from Batman Beyond.
- At Wayne Manor's private playground, Bruce Wayne is seen sliding down a pole before walking towards Arthur Fleck at the gates. This seems to be an allusion to the Batpole from the 1966 television series Batman.
- A green question mark graffiti is seen in the elevator at Arkham State Hospital, presumably a reference to the Riddler.
- Penny Fleck's former therapist at Arkham State Hospital is identified as Dr. Benjamin Stoner. In the DC Comics, Benjamin Stoner was one of the head doctors at Arkham Asylum and an enemy to Doctor Fate.
- Arthur's deadly appearance at the Murray Franklin show is reminiscent of Batman: The Dark Knight Returns #3, where the Joker makes a similarly shocking talk show appearance.
- No trivia.
Links and References