Kosinek [kɔˈɕinɛk] (German: Augustenruh) is a settlement in the administrative district of Gmina Bierzwnik, within Choszczno County, West Pomeranian Voivodeship, in north-western Poland. It lies approximately 7 kilometres (4 mi) north-west of Bierzwnik, 17 km (11 mi) south-east of Choszczno, and 77 km (48 mi) south-east of the regional capital Szczecin.

For the history of the region, see History of Pomerania.