Koszelew [kɔˈʂɛlɛf] is a village in the administrative district of Gmina Gąbin, within Płock County, Masovian Voivodeship, in east-central Poland. It lies approximately 3 kilometres (2 mi) west of Gąbin, 18 km (11 mi) south of Płock, and 92 km (57 mi) west of Warsaw.