Kosewo [kɔˈsɛvɔ] is a village in the administrative district of Gmina Stary Lubotyń, within Ostrów Mazowiecka County, Masovian Voivodeship, in east-central Poland. It lies approximately 3 kilometres (2 mi) south-west of Stary Lubotyń, 13 km (8 mi) north of Ostrów Mazowiecka, and 99 km (62 mi) north-east of Warsaw.