Czarnia [ˈt͡ʂarɲa] is a village in Ostrołęka County, Masovian Voivodeship, in east-central Poland. It is the seat of the gmina (administrative district) called Gmina Czarnia. It lies approximately 40 kilometres (25 mi) north-west of Ostrołęka and 127 km (79 mi) north of Warsaw.