Brzeźnica [bʐɛʑˈnit͡sa] (German: Birkenwerder) is a village in the administrative district of Gmina Kętrzyn, within Kętrzyn County, Warmian-Masurian Voivodeship, in northern Poland. It lies approximately 4 kilometres (2 mi) south of Kętrzyn and 65 km (40 mi) north-east of the regional capital Olsztyn.