The Potsdam Agreement was the agreement among three of the Allies of World War II: the United Kingdom, the United States, and the Soviet Union after the war ended in Europe on 1 August 1945 and it was published the next day. A product of the Potsdam Conference, it concerned the military occupation and reconstruction of Germany, its border, and the entire European Theatre of War territory. It also addressed Germany's demilitarisation, reparations, the prosecution of war criminals and the mass expulsion of ethnic Germans from various parts of Europe. France was not invited to the conference but formally remained one of the powers occupying Germany.

The entirety of Germany was occupied and administered by the Allies of World War II from the Berlin Declaration on 5 June 1945 to the establishment of West Germany on 23 May 1949. Unlike occupied Japan, Germany was stripped of its sovereignty and former state: after Nazi Germany surrendered on 8 May 1945, four countries representing the Allies asserted joint authority and sovereignty through the Allied Control Council (ACC). At first, Allied-occupied Germany was defined as all territories of Germany before the 1938 Nazi annexation of Austria; the Potsdam Agreement on 2 August 1945 defined the new eastern German border by giving Poland and the Soviet Union all regions of Germany east of the Oder–Neisse line and divided the remaining "Germany as a whole" into four occupation zones, each administered by one of the Allies.