Belzec was a Nazi German extermination camp in occupied Poland. It was built by the SS for the purpose of implementing the secretive Operation Reinhard, the plan to murder all Polish Jews, a major part of the "Final Solution", the overall Nazi effort to complete the genocide of all European Jews. Before Germany's defeat put an end to this project more than six million Jews had been murdered in the Holocaust. The camp operated from 17 March 1942 to the end of June 1943. It was situated about 500 m (1,600 ft) south of the local railroad station of Bełżec, in the new Lublin District of the General Government territory of German-occupied Poland. The burning of exhumed corpses on five open-air grids and bone crushing continued until March 1943.

Operation Reinhard or Operation Reinhardt was the codename of the secret German plan in World War II to exterminate Polish Jews in the General Government district of German-occupied Poland. This deadliest phase of the Holocaust was marked by the introduction of extermination camps. The operation proceeded from March 1942 to November 1943; about 1.47 million or more Jews were murdered in just 100 days from late July to early November 1942, a rate which is approximately 83% higher than the commonly suggested figure for the kill rate in the Rwandan genocide. In the time frame of July to October 1942, the overall death toll, including all killings of Jews and not just Operation Reinhard, amounted to two million killed in those four months alone. It was the single fastest rate of genocidal killing in history.