Mierucin [mjɛˈrut͡ɕin] is a village in the administrative district of Gmina Sośno, within Sępólno County, Kuyavian-Pomeranian Voivodeship, in north-central Poland. It lies approximately 10 kilometres (6 mi) south of Sośno, 21 km (13 mi) south-east of Sępólno Krajeńskie, and 29 km (18 mi) north-west of Bydgoszcz.