Buk [buk] is a village in the administrative district of Gmina Cisna, within Lesko County, Subcarpathian Voivodeship, in south-eastern Poland, close to the border with Slovakia. It lies approximately 6 kilometres (4 mi) north-east of Cisna, 26 km (16 mi) south of Lesko, and 92 km (57 mi) south of the regional capital Rzeszów.