Olszewnik [ɔlˈʂɛvnik] is a village in the administrative district of Gmina Jeziorany, within Olsztyn County, Warmian-Masurian Voivodeship, in northern Poland. It lies approximately 4 kilometres (2 mi) east of Jeziorany and 29 km (18 mi) north-east of the regional capital Olsztyn.