Kosewo [kɔˈsɛvɔ] is a village in the administrative district of Gmina Ostrowite, within Słupca County, Greater Poland Voivodeship, in west-central Poland. It lies approximately 8 kilometres (5 mi) west of Ostrowite, 13 km (8 mi) north-east of Słupca, and 71 km (44 mi) east of the regional capital Poznań.