Kwidzyn Castle (German: Burg Marienwerder) is a large brick gothic castle in the town of Kwidzyn, Poland. It is an example of Teutonic Knights' castles architecture.
The castle is located by Gdańska Street (Ulica Gdańska in Polish) in Kwidzyn. The castle was used as a chapter house for the Pomesanians, who built it at the beginning of the 14th century - in a square formation with a courtyard and square keeps in the corners of the castle's square formation; and a dansker supported by five arcades. King Władysław II Jagiełło took over the castle, while heading battles against the Teutonic Knights in 1410. The Second Peace of Toruń ceded the castle to the Teutonic Knights.
During the 17th century Deluge campaigns, the Swedes partially destroyed the castle. Prussian authorities had ordered to partially deconstruct the castle in the 18th century. In 1855-1875 the castle underwent a reconstruction.
Currently, the preserved north-western and western wing houses the Branch of the Castle Museum in Malbork (Oddział Muzeum Zamkowego w Malborku in Polish). The largest dansker and a well with a porch have also been preserved.