Brzeziniak [bʐɛˈʑiɲak] (German Birkenthal) is a settlement in the administrative district of Gmina Zalewo, within Iława County, Warmian-Masurian Voivodeship, in northern Poland. It lies approximately 3 kilometres (2 mi) north-west of Zalewo, 30 km (19 mi) north of Iława, and 61 km (38 mi) west of the regional capital Olsztyn.