American gangster who became a top crime boss in Chicago and, later, one of the founders of modern organized crime in America.

Born in a village near Naples, Torrio was brought to New York City by his widowed mother when he was two. He became a brothel-saloonkeeper and leader of the James Street Boys, allying them with the Five Points Gang (1904–08). He then rose to become a rackets boss (i.e., engaged in activities involving extortion) in Brooklyn before being called to Chicago in 1909 to operate and expand Big Jim (Colosimo, James) Colosimo's chain of brothels. In 1919 Torrio summoned his old friend Al Capone (Capone, Al) from New York to manage one of the brothels and, in 1920, had either him or Frankie Yale murder Colosimo. Torrio thereby inherited Colosimo's empire and immediately expanded into big-time bootlegging (illegal manufacture, sale, and transport of alcohol) and gambling casinos of the Prohibition era.

In 1925, after successively being shot at and wounded by a rival gang and serving nine months in prison for operating a brewery, Torrio turned over his rackets to Capone and retired to Italy (1925–28). Returning to live in New York, he invested profitably in real estate and helped create a bootlegging combine, becoming a close associate of Lucky Luciano, Meyer Lansky, and other bosses. Torrio was one of the directors of the national crime syndicate or cartel formed in 1934.

In 1936 he was charged with income tax evasion and, after a long trial and many appeals, went to prison again (1939–41). He subsequently went into virtual retirement, very wealthy, and died of a heart attack in a barber chair in 1957.