Olszewo [ɔlˈʂɛvɔ] is a village in the administrative district of Gmina Nidzica, within Nidzica County, Warmian-Masurian Voivodeship, in northern Poland. It lies approximately 3 kilometres (2 mi) west of Nidzica and 49 km (30 mi) south of the regional capital Olsztyn.