Ostrogozhsk (Russian: Острого́жск) is a town and the administrative center of Ostrogozhsky District in Voronezh Oblast, Russia, located on the Tikhaya Sosna River (a tributary of the Don), 142 kilometers (88 mi) south of Voronezh, the administrative center of the oblast.

It was established in 1652 by Belgorod Voivode Fedor Arsenyev and Cossack Ivan Zevkovsky (or Dzenkovsky) as Ostogozhsk (little fortress) bringing along some 2,000 resettlers from Chernigov and Nezhin Regiments around an ostrog (fortress) of the Belgorod Defensive Line of Russia.

[10][11][12] During the time of Stepan Razin's revolt against Aleksey Mikhailovich of Russia the city was under control of rebellious Cossacks.

[16] The town served as the headquarters of a Sloboda Ukrainian Cossack territorial and military regiment until the 1760s when it was abolished by Catherine II.

The town was occupied by Nazi Germany during World War II from July 5, 1942 (during the Battle of Voronezh) to January 20, 1943, when it was liberated in the course of the Ostrogozhsk–Rossosh Offensive.