Chernyakhovsk ; prior to 1946 known by its German name (; ) is a town and the administrative center of Chernyakhovsky District in Kaliningrad Oblast, Russia, located at the confluence of the Instruch and Angrapa Rivers, forming the Pregolya. Population:

It was founded in 1336, after the Prussian Crusade, when the Grand Master of the Teutonic Knights Dietrich von Altenburg built a castle called Instierburg at the site of a former Old Prussian fortification. During their campaign against the Grand Duchy of Lithuania, the place was devastated in 1376 and again by Polish troops in 1457. The castle had been rebuilt as the seat of a Procurator and a settlement grew up to serve it, also called Insterburg.