Carl Williams (13 October 1970[2] – 19 April 2010) was an Australian convicted murderer and drug trafficker from the state of Victoria. He was the central figure in the Melbourne gangland killings. Williams attended Broadmeadows West Technical School, leaving in Year 11. Williams spent much of his childhood in Western Melbourne with his friends and older brother Shane who died of a heroin overdose in 1997. He was married to convicted drug trafficker Roberta Williams (born 23 March 1969), with whom he had one child, born 10 March 2001. Williams held various labouring jobs before opening a children’s clothing store in partnership with his wife, which eventually failed. Williams’ mother Barbara was found dead in her Melbourne home on 22 November 2008. She had been suffering from depression. On 25 November 1999, Carl Williams, along with his father, George and another associate, was arrested and charged with drug trafficking after a raid on a Broadmeadows illegal drug factory. In excess of 250,000 amphetamine tablets were seized by police, estimated to be worth up to $20 million. Williams, who described himself as a semi-professional gambler, was banned from the Crown Casino complex on 2 April 2004 by police commissioner Christine Nixon under the Casino Control Act.

Carl Williams was sentenced to life imprisonment with a non-parole period of 35 years for ordering the murders of three people and conspiracy to murder a fourth (which was unsuccessful). On 19 April 2010, while incarcerated at Barwon Prison, Williams was beaten to death with the stem of an exercise bike by another inmate, Matthew Charles Johnson. Williams enlisted the help of others willing to perform the contract killings in exchange for large payments of cash. At the time of his death, he was in the maximum security Acacia unit of HM Prison Barwon near Geelong. Williams would have been 71 before he was eligible for parole.