Ostrówek [ɔsˈtruvɛk] is a village in the administrative district of Gmina Sośno, within Sępólno County, Kuyavian-Pomeranian Voivodeship, in north-central Poland. It lies approximately 8 kilometres (5 mi) south-west of Sośno, 13 km (8 mi) south-east of Sępólno Krajeńskie, and 37 km (23 mi) north-west of Bydgoszcz.