Olszanica [ɔlʂaˈɲit͡sa] is a village in the administrative district of Gmina Sadlinki, within Kwidzyn County, Pomeranian Voivodeship, in northern Poland. It lies approximately 3 kilometres (2 mi) north-west of Sadlinki, 9 km (6 mi) south-west of Kwidzyn, and 78 km (48 mi) south of the regional capital Gdańsk.

For the history of the region, see History of Pomerania.