Richard Leonard Kuklinski (; April 11, 1935 – March 5, 2006), also known as the Iceman, was an American criminal and a convicted murderer. He was engaged in criminal activities for most of his adult life; he ran a burglary ring and distributed pirated pornography. Kuklinski committed at least five murders between 1980 and 1984. Prosecutors described him as killing for profit. He was nicknamed the "Iceman" by authorities after they discovered that he had frozen the body of one of his victims in an attempt to disguise the time of death.

Kuklinski lived with his wife and children in the New Jersey suburb of Dumont. They knew him as a loving father and husband, although one who also had a violent temper. Kuklinski's family stated that they were unaware of his crimes. Kuklinski's modus operandi was to lure men to clandestine meetings with the promise of lucrative business deals, then kill them and steal their money. He also killed two associates to prevent them from becoming informants. Eventually, Kuklinski came to the attention of law enforcement when an investigation into his burglary gang linked him to several murders, as he was the last person to have seen five missing men alive. An eighteen-month-long undercover operation led to his arrest in December 1986. In 1988, he was convicted of four murders and sentenced to life imprisonment. In 2003, Kuklinski received an additional 30-year sentence after confessing to the 1980 murder of an NYPD detective.

After his murder convictions, Kuklinski gave interviews to writers, prosecutors, criminologists, and psychiatrists. He claimed to have murdered anywhere from 100 to 200 men, often in gruesome fashion. None of these additional murders have been corroborated. In 2020, ATF Special Agent Dominick Polifrone said, "I don't believe he killed two-hundred people. I don't believe he killed a hundred people. I'll go as high as 15, maybe." Kuklinski also claimed to have worked as a hitman for the Mafia. He said he participated in several famous Mafia killings, including the disappearance and presumed murder of Teamsters' president Jimmy Hoffa. Law enforcement and organized crime experts have expressed skepticism about Kuklinski's claimed Mafia ties. He was the subject of three HBO documentaries aired in 1992, 2001 and 2003; several biographies, and a 2012 feature film The Iceman.