Ozyorsk ( ), known prior to 1938 by its German name   ( ; ), and from 1938 to 1946 as Angerapp, is a town and the administrative center of Ozyorsky District in Kaliningrad Oblast, Russia, located on the Angrapa River near the border with the Polish Warmian-Masurian Voivodeship, 120 kilometers southeast of Kaliningrad, the administrative center of the oblast.