The Holocaust, also known as the Shoah, was the World War II genocide of the European Jews. Between 1941 and 1945, across German-occupied Europe, Nazi Germany and its collaborators systematically murdered some six million Jews, around two-thirds of Europe's Jewish population.

The murders were carried out in pogroms and mass shootings; by a policy of extermination through work in concentration camps; and in gas chambers and gas vans in German extermination camps, such as Auschwitz-Birkenau, Bełżec, Chełmno, Majdanek, Sobibór, and Treblinka in occupied Poland.

Germany implemented the persecution in stages. Following Adolf Hitler's appointment as Chancellor on 30 January 1933, the regime built a network of concentration camps in Germany for political opponents and those deemed "undesirable", starting with Dachau on 22 March 1933. After the passing of the Enabling Act on 24 March, which gave Hitler plenary powers, the government began isolating Jews from civil society; this included boycotting Jewish businesses in April 1933 and enacting the Nuremberg Laws in September 1935. On 9–10 November 1938, eight months after Germany annexed Austria, Jewish businesses and other buildings were ransacked, smashed or set on fire throughout Germany and Austria during what became known as Kristallnacht (the "Night of Broken Glass").

After Germany invaded Poland in September 1939, triggering World War II, the regime set up ghettos to segregate Jews from the rest of the population. Eventually thousands of camps and other detention sites were established across German-occupied Europe.

As German forces captured territories in the East, all anti-Jewish measures were radicalized. Under the coordination of the SS, with directions from the highest leadership of the Nazi Party, killings were committed within Germany itself, throughout occupied Europe, and within territories controlled by Germany's allies. Paramilitary death squads called Einsatzgruppen, in cooperation with the German Army and local collaborators, murdered around 1.3 million Jews in mass shootings and pogroms between 1941 and 1945. By mid-1942, victims were being deported from ghettos across Europe in sealed freight trains to extermination camps where, if they survived the journey, they were worked to death or gassed. The killing continued until the end of World War II in Europe in May 1945.

The European Jews were targeted for extermination as part of a larger event during the Holocaust era, usually defined as beginning in January 1933, in which Germany and its collaborators persecuted and murdered other groups, including Slavs (chiefly ethnic Poles, Soviet civilians and Soviet prisoners of war), the Roma, the "incurably sick", political and religious dissidents, and gay men.  The death toll of these groups is thought to rise to 11 million.