Rościmin [rɔɕˈt͡ɕimin] is a village in the administrative district of Gmina Mrocza, within Nakło County, Kuyavian-Pomeranian Voivodeship, in north-central Poland. It lies approximately 8 kilometres (5 mi) north-west of Mrocza, 18 km (11 mi) north of Nakło nad Notecią, and 39 km (24 mi) north-west of Bydgoszcz.