Gusev is a town and the administrative center of Gusevsky District of Kaliningrad Oblast, Russia, located at the confluence of the Pissa and Krasnaya Rivers, near the border with Poland and Lithuania, east of Chernyakhovsk. Population: 28,177 (2021 Census); 28,260 (2010 Russian census); 28,467 (2002 Census); 27,031 (1989 Soviet census).

Kaliningrad Oblast is the westernmost federal subject of the Russian Federation, in Central and Eastern Europe. It is a semi-exclave situated on the Baltic Sea. The oblast is surrounded by two European Union and NATO members: Poland to the south and Lithuania to the north and east. The largest city and administrative centre of the province (oblast) is the city of Kaliningrad, formerly known as Königsberg. The port city of Baltiysk is Russia's only port on the Baltic Sea that remains ice-free in winter. Kaliningrad Oblast had a population of roughly 1 million in the Russian Census of 2021.