The Schutzstaffel ("Protection Squadron"), abbreviated SS, was a major paramilitary organization under Adolf Hitler and the Nazi Party in Nazi Germany, and later throughout German-occupied Europe during World War II. Originally a volunteer bodyguard and VIP security unit, following the appointment of Heinrich Himmler as leader, it rapidly expanded into a semi-independent organization embodying Nazi racial ideology and an occult neo-paganism. Unlike the Sturmabteilung, the SS preached total obedience to Hitler, considering itself the Party's ideological and racial elite; in 1936 it gained control of all police services, and in 1939 was granted immunity from prosecution in civil courts.

The SS was organized into three principal branches: the Allgemeine SS (enforcement of racial policy and general policing), Waffen-SS (frontline combat), and Totenkopfverbände (SS-TV), which operated the concentration and extermination camps. The SS also managed the secret police (Gestapo) and its sister intelligence office, the Sicherheitsdienst. The SS was the principal orchestrator of the Holocaust, with planning entrusted to Himmler and implementation carried out by his deputy, Reinhard Heydrich. At the war's end, all SS offices were declared criminal organizations both independently and by association.