Gmina Karsin is a rural gmina (administrative district) in Kościerzyna County, Pomeranian Voivodeship, in northern Poland. Its seat is the village of Karsin, which lies approximately 24 kilometres (15 mi) south of Kościerzyna and 69 km (43 mi) south-west of the regional capital Gdańsk. The gmina covers an area of 169.2 square kilometres (65.3 sq mi), and as of 2006 its total population is 5,905. The gmina contains part of the protected area called Wdydze Landscape Park.