Dolnik [ˈdɔlnik] (German: Wittenburg; before 1926: Dollnik) is a village in the administrative district of Gmina Krajenka, within Złotów County, Greater Poland Voivodeship, in northwestern Poland. It lies approximately 7 kilometres (4 mi) south-west of Krajenka, 14 km (9 mi) south-west of Złotów, and 97 km (60 mi) north of the regional capital Poznań.
Before 1772 the area was part of Kingdom of Poland, 1772-1945 Prussia and Germany. For more on its history, see Złotów County.
The village has a population of 160.