The Polish Corridor, also known as the Danzig Corridor, Corridor to the Sea or Gdańsk Corridor, was a territory located in the region of Pomerelia, which provided the Second Republic of Poland (1920–1939) with access to the Baltic Sea, thus dividing the bulk of Weimar Germany from the province of East Prussia. At its narrowest point, the Polish territory was just 30 km wide. The Free City of Danzig, situated to the east of the corridor, was a semi-independent German speaking city-state forming part of neither Germany nor Poland, though united with the latter through an imposed union covering customs, mail, foreign policy, railways as well as defence.

Pomerania is a historical region on the southern shore of the Baltic Sea in Central Europe, split between Poland and Germany. The central and eastern part belongs to the West Pomeranian, Pomeranian and Kuyavian-Pomeranian voivodeships of Poland, while the western part belongs to the German states of Mecklenburg-Western Pomerania and Brandenburg.