Dzerzhinsk (Russian: Дзержинск, IPA: [dʲzʲɪˈrʐɨnsk]) is a city in Nizhny Novgorod Oblast, Russia, located along the Oka River, about 400 kilometers (250 mi) east of Moscow. Population: 240,742 (2010 Census); 261,334 (2002 Census); 285,071 (1989 Census).

Within the framework of administrative divisions, it is, together with three work settlements and eleven rural localities, incorporated as the city of oblast significance of Dzerzhinsk—an administrative unit with a status equal to that of the districts. As a municipal division, the city of oblast significance of Dzerzhinsk is incorporated as Dzerzhinsk Urban Okrug.