Lubnica [lubˈnit͡sa] (German: Groß Hertzberg) is a village in the administrative district of Gmina Okonek, within Złotów County, Greater Poland Voivodeship, in west-central Poland. It lies approximately 12 kilometres (7 mi) north of Okonek, 33 km (21 mi) north of Złotów, and 138 km (86 mi) north of the regional capital Poznań.
Before 1945 the area was part of Germany. For more on its history, see Złotów County.
The village has a population of 110.