Richard Leonard "The Iceman" Kuklinski (April 11, 1935 – March 5, 2006) was an American contract killer who was convicted for three murders. Kuklinski was given the nickname "Iceman" for his method of freezing a victim to mask the time of death. The 6'5" (196 cm), 300 pound (135 kg) Kuklinski lived with his wife and children in the suburb of Dumont, New Jersey. Prior to his arrest, his family was apparently unaware of Kuklinski's double life and crimes. A New Jersey Police task force was formed after Kuklinski was suspected of five murders. A year-long undercover investigation led to his arrest. It is believed by the FBI that Kuklinski killed at least 250 people for the Gambino Crime Family. Fellow mobsters called Kuklinski "The Juggernaut", "The Beast", "The One-Man Wrecking Machine", or "The Big Demon."

Kuklinski was a contract killer for the New York Mafia. After his murder convictions, Kuklinski took part in a number of interviews during which he claimed to have murdered over 250 to 400 people (his "recollections" varied) between 1956 and 1986. Three documentaries, two biographies and a feature film have been produced on Kuklinski based on his interviews and the results of the task force that brought Kuklinski to justice.