Wykosowo is a village in the administrative district of Gmina Główczyce, within Słupsk County, Pomeranian Voivodeship, in northern Poland. It lies approximately 5 km east of Główczyce, 32 km north-east of Słupsk, and 82 km west of the regional capital Gdańsk. Before 1648, the area was part of Duchy of Pomerania, and in 1648–1945 it belonged to Prussia and Germany. For the history of the region, see History of Pomerania. There is palace and folwark buildings, all originating from the end of the 19th century.