Postolin [pɔsˈtɔlin] is a village in the administrative district of Gmina Sztum, within Sztum County, Pomeranian Voivodeship, in northern Poland. It lies approximately 6 kilometres (4 mi) south of Sztum and 62 km (39 mi) south-east of the regional capital Gdańsk.

Before 1772 the area was part of Kingdom of Poland, and in 1772–1945 it belonged to Prussia and Germany. For the history of the region, see History of Pomerania.