Stieg Larsson, original name Karl Stig-Erland Larsson, (born August 15, 1954, Skelleftehamn, Sweden—died November 9, 2004, Stockholm), Swedish writer and activist whose posthumously published Millennium series of crime novels brought him international acclaim.

Larsson grew up with his maternal grandparents in northern Sweden until age nine, when he rejoined his parents in Stockholm. As a teenager he wrote obsessively and, inspired by his grandfather’s ardent antifascist beliefs, developed an interest in radical leftist politics. Following a mandatory 14-month stint in the Swedish army, Larsson participated in rallies against the Vietnam War and became involved in a revolutionary communist group, through which he briefly edited a Trotskyist journal. In 1977, after traveling to Ethiopia to train Eritrean dissidents, he landed a job as a graphic designer for the Swedish news agency Tidningarnas Telegrambyrå (TT), where he later worked as a journalist as well and would remain for 22 years. He soon began to also pen articles for Searchlight, a British magazine that investigated and exposed fascism.