Charles Milles Manson (born November 12, 1934) is an American criminal who led what became known as the Manson Family, a quasi-commune that arose in California in the late 1960s. He was convicted of conspiracy to commit the Tate/LaBianca murders, carried out by members of the group at his instruction. He was found guilty of the murders themselves through the joint-responsibility rule, which makes each member of a conspiracy guilty of crimes his fellow conspirators commit in furtherance of the conspiracy's object.

Manson is associated with "Helter Skelter," the term he took from the Beatles song of that name and construed as an apocalyptic race war the murders were putatively intended to precipitate. This connection with rock music linked him, from the beginning of his notoriety, with pop culture, in which he became an emblem of insanity, violence, and the macabre. Ultimately, the term was used as the title of the book that prosecutor Vincent Bugliosi wrote about the Manson murders.

At the time the Family began to form, Manson was an unemployed ex-convict, who had spent half his life in correctional institutions for a variety of offenses. In the period before the murders, he was a distant fringe member of the Los Angeles music industry, chiefly via a chance association with Beach Boy Dennis Wilson. After Manson was charged with the crimes, recordings of songs written and performed by him were released commercially. Artists including Guns N' Roses and Marilyn Manson have covered his songs in the decades since.