The global success of Nordic noir in the early twenty-first century has propelled Swedish crime fiction to the centre of the global crime fiction universe. It is associated with authors such as Maj Sjöwall and Per Wahlöö, Henning Mankell, and Stieg Larsson, and their gloomy depictions of the Nordic welfare state. But the national genre tradition is both much broader and older than this image suggests. “Deckare”—as the genre is still called in Swedish, referring to an old Swedish nickname for the classic detective figure—has been one of the most important genres in Sweden since the late nineteenth century, with a deep influence on literature in general as well as broader cultural trends. This entry tells the story of Swedish crime fiction from its roots, via the heyday of classic detective fiction in the mid-twentieth century, to the Nordic noir boom and beyond.