Kolaigaran (transl. Killer) is a 2019 Indian Tamil-language action thriller film directed by Andrew Louis. The film stars Arjun Sarja, Vijay Antony and Ashima Narwal, while Nassar and Seetha play supporting roles. The music was scored by Simon K. King. Principal photography of the film commenced on 5 June 2018. The film follows an investigation in which a woman and her mother are suspected of murder after a disfigured corpse is found, while their neighbour claims to have committed it instead, much to the surprise of cops. The film was released theatrically on 7 June 2019. It opened to positive reviews and became a super hit at the box office.

It is an uncredited remake of the 2012 South Korean thriller film Perfect Number, which was based on the 2005 Japanese mystery novel The Devotion of Suspect X by Keigo Higashino. Kross Pictures, the South Korean film company which held the adaptation rights of the novel and film, sued the makers of Kolaigaran and won a copyright infringement suit in 2019. Kross Pictures later themselves released Jaane Jaan, an official Indian adaptation of the novel and film in 2023.