Ostaszewo [ɔstaˈʂɛvɔ] is a village in Nowy Dwór Gdański County, Pomeranian Voivodeship, in northern Poland. It is the seat of the gmina (administrative district) called Gmina Ostaszewo. It lies approximately 12 kilometres (7 mi) west of Nowy Dwór Gdański and 27 km (17 mi) south-east of the regional capital Gdańsk.

Before 1772 the area was part of Kingdom of Poland, 1772-1919 Prussia and Germany, 1920-1939 Free City of Danzig, 1939 - February 1945 Nazi Germany. For the history of the region, see History of Pomerania.