Kwidzyn (; Latin: Quedin; ; Prussian: Kwedina) is a town in northern Poland on the Liwa river in the Powisle (right bank of Vistula) region, with 40,008 inhabitants (2004). It has been a part of the Pomeranian Voivodeship since 1999, and was previously in the Elblag Voivodeship (1975–1998). It is the capital of Kwidzyn County.