Carlo Tresca (March 9, 1879 – January 11, 1943) was an Italian-born American newspaper editor, orator, and labor organizer who was a leader of the Industrial Workers of the World during the decade of the 1910s. Tresca is remembered as a leading public opponent of fascism, Stalinism, and Mafia infiltration of the trade union movement. Tresca was assassinated by a Mafia gunman in 1943.