Martin ‘Marty’ Faranan
Played By: Colin Farrell
- Jerkass: Especially when he's drunk.
- Most Writers Are Writers: Marty is a struggling writer who dreams of finishing his screenplay "Seven Psychopaths".
- National Stereotypes: He's an alcholic Irish writer. Billy even lampshades it.
- Shut Up, Hannibal!: When Charlie is mocking Marty over his men killing Hans:Charlie: Don't you wish you had a gun now?Marty: ...No, I don't. So why don't you go fuck yourself?
- Supporting Protagonist: Billy even points out that Marty's role is observing, and that nobody thinks he's a pussy for it.
Played By: Christopher Walken
- Real Men Love Jesus: He's a very devout old-fashioned Christian. His faith is specifically mentioned as the source of his confidence and tranquility.
Played By: Sam Rockwell
- Affably Evil: He really does want to be Marty's friend. Too bad he's a jerk at best and a sociopath at worst.
- Anti-Hero: Mixture of a Type IV and V.
- Even Evil Has Standards: in his script animals don't die at the end he puts his life on the line not to kill Bonnie, the dog
- The Heavy: None of the movie would have happened without Billy's actions.
- Jerk with a Heart of Gold: Emphasis on the "jerk", but he does want to be a good friend to Marty. Just that often times, his obnoxiousness and psychopathy gets the better of him.
- Psychopathic Manchild: Of the obnoxious and unpredictable variety.
- Serial-Killer Killer: Arguably so, since most of the mid-level mafia and Yakuza sorts he's targeted, such as the hitmen in the intro, are all killers.
Played By: Woody Harrelson
- Faux Affably Evil: Charlie can be pretty well spoken and have moments of genuine kindness to Bonnie, but he's mentally unstable and will pretty much kill anything that moves.
- Hair-Trigger Temper: When it comes to his dog. Granted, he is a psychopath, but when his dog walker loses his Shih Tzu, he has her hunted down, tied to a chair, and then starts threatening to murder her. He does settle for shooting the wall behind her when she's found innocent, however.
- Only a Flesh Wound: Double-subverted. When Charlie arrives to reclaim his dog, he makes a show of being unarmed. Billy shoots him in the spine, and then is disgusted to find he was unarmed (save for a flare gun). For the next few minutes, Charlie's paralyzed and helpless, unable to move his legs... until Marty helps him back to his car. Then he's back to normal, revealing that Billy only clipped him ("Just a flesh wound, kid"), and grabs a gun from his glove compartment.
- Pet the Dog: Literally, in the case of his genuine concern for his dog, Bonnie. He also lets his dog caretaker live after finding out about the scam Billy and Hans run, realizing she wasn't at fault.
- Politically Incorrect Villain: Charlie makes racist and homophobic comments throughout.
- Psychopathic Manchild: Of the unstable and dangerous variety.
Played By: Tom Waits
- Affably Evil: He's nothing but polite and friendly to Marty. He even spares Marty when its clear he's been having a rough time.
- Disproportionate Retribution: Marty forgot to put the message to Maggie at the end of the film? Better go kill him.
- Even Evil Has Standards: He’s disturbed by his girlfriend’s level of brutality.
- Outlaw Couple: With Maggie in the past, two Serial Killers (or Killer Killers) in love who indulged in some spectacularly over-the-top violence.
- Serial-Killer Killer: In the past, where he and Maggie would presumably go hunting for the worst of the worst. We don't see a whole lot of this, though, so how much of it is actually true is a mystery.
Played By: Abbie Cornish
- Advertised Extra: She's on the cover with the rest of the characters, but her effect on the plot is actually rather minimal.
Played By: Olga Kurylenko
Played By: Željko Ivanek
- Mistreatment-Induced Betrayal: He doesn’t actively betray Charlie, but does get fed up when his boss tries to shift blame to him.
Played By: Linda Bright Clay
Played By: Kevin Corrigan
Larry and Tommy
Played By: Michael Pitt and Michael Stuhlbarg
- Boom, Headshot: They are killed after a man in a mask shoots their heads off.
- The Cameo: They only appear at the start of the movie before being killed off.
- Seinfeldian Conversation: Their conversation at the beginning.
- Surprisingly Sudden Death: They start the movie while discussing various topics. Suddenly, a man in a mask walks up and blows both of their heads off.