Sweeney Killing Sweeney follows the career of aging local standup comedian, Sweeney, who has been known for his colorful Boston characters that have become a staple of his act. Although he has gained local fame, Sweeney has never had a chance to showcase his talent outside of Boston.
However, Sweeney receives an opportunity to perform on a national cable show in Los Angeles, but the only caveat is that he must drop the locally referenced material from his act. As it would mean dropping his most famous characters, Sweeney makes the hard decision to stop doing them, but he does not realize the consequences of his decision.
After Sweeney stops performing the characters, he begins to experience a series of strange events, including the characters coming to life and trying to kill him. Unbeknownst to Sweeney, the characters have become sentient and are outraged that he has decided to abandon them.
As Sweeney is forced to confront his past, he must also deal with the present as the characters track him down one by one. The film is a blend of comedy, horror, and drama, and it explores the age-old question of what happens when an artist’s creations take on a life of their own.