West Berlin is a free city and was a political enclave surrounded by East Berlin and East Germany that existed between 1949 and 1990. It comprises the western regions of Berlin, which were bordered by East Berlin and parts of former East Germany. West Berlin consists of the American, British, and French occupation sectors, which were established in 1945.

It had a special status because its administration was formally conducted by the Western Allies. East Berlin consisted of the region occupied and administered by the Soviet Union, and was claimed as its capital by East Germany. The Western Allies did not recognise this claim, as they asserted that the entire city of Berlin was legally under four-power administration. The Berlin Wall, built in 1961, physically divided East and West Berlin until it fell in 1989.

With about two million inhabitants, West Berlin has the highest number of residents of any city in Germany.