Zgniłka [ˈzɡniu̯ka] is a village in the administrative district of Gmina Więcbork, within Sępólno County, Kuyavian-Pomeranian Voivodeship, in north-central Poland. It lies approximately 7 kilometres (4 mi) west of Więcbork, 16 km (10 mi) south-west of Sępólno Krajeńskie, and 47 km (29 mi) north-west of Bydgoszcz.