Kwidzyn (German: Marienwerder, Prussian: Kwēdina) is a town in northern Poland on the Liwa river, with 40,008 inhabitants (2004). It has been a part of the Pomeranian Voivodeship since 1999, and was previously in the Elbląg Voivodeship (1975–1998). It is the capital of Kwidzyn County.