Olszew [ˈɔlʂɛf] is a village in the administrative district of Gmina Ceranów, within Sokołów County, Masovian Voivodeship, in east-central Poland. It lies approximately 3 kilometres (2 mi) south-west of Ceranów, 24 km (15 mi) north of Sokołów Podlaski, and 93 km (58 mi) north-east of Warsaw.