Karl Stig-Erland "Stieg" Larsson (/stiːɡ ˈlɑːrsən/; Swedish pronunciation: [ˈkɑːɭ ˈstiːɡ ˈæːɭand ˈlɑːʂɔn]; 15 August 1954 – 9 November 2004) was a Swedish journalist and writer. He is best known for writing the Millennium trilogy of crime novels, which were published posthumously and adapted as motion pictures. Larsson lived much of his life in Stockholm and worked there in the field of journalism and as an independent researcher of right-wing extremism.

He was the second best-selling author in the world for 2008, behind Khaled Hosseini. The third novel in the Millennium trilogy, The Girl Who Kicked the Hornets' Nest, became the most sold book in the United States in 2010, according to Publishers Weekly. By March 2015, his series had sold 80 million copies worldwide.