Kościerzyna County (Kashubian: Kòscérsczi kréz, Polish: powiat kościerski) is a unit of territorial administration and local government (powiat) in Pomeranian Voivodeship, northern Poland. It came into being on 1 January 1999 as a result of the Polish local government reforms passed in 1998. Its administrative seat and only town is Kościerzyna, which lies 51 kilometres (32 mi) south-west of the regional capital Gdańsk. Its borders equal approximately the borders of the old Marquessate of Berent in the German Empire. Kościerzyna County on a map of the counties of Pomeranian Voivodeship