Borsk is a village in the administrative district of Gmina Karsin, within Kościerzyna County, Pomeranian Voivodeship, in northern Poland. It lies approximately 6 kilometres (4 mi) north of Karsin, 19 km (12 mi) south of Kościerzyna, and 66 km (41 mi) south-west of the regional capital Gdańsk. It is located within the ethnocultural region of Kashubia in the historic region of Pomerania.