Ostrov (Russian: О́стров, lit. island) is a town and the administrative center of Ostrovsky District of Pskov Oblast, Russia, located on the Velikaya River, 55 kilometers (34 mi) south of Pskov. Municipally, it is incorporated as Ostrov Urban Settlement in Ostrovsky Municipal District. Population: 21,668 (2010 Census); 25,078 (2002 Census); 29,060 (1989 Census); 27,000 (1974).
Ostrov was founded as a fortress in the end of the 13th century and first mentioned under 1342. It had been an important military outpost throughout the 15th-16th centuries. In particular, the only time it was conquered was 1501 (by the Livonian Order after the Battle of the Siritsa River). In the course of the administrative reform carried out in 1708 by Peter the Great, the area was included into Ingermanland Governorate (known since 1710 as Saint Petersburg Governorate). Ostrov is specifically mentioned as one of the towns making the governorate. In 1727, separate Novgorod Governorate was split off, and in 1772, Pskov Governorate (which between 1777 and 1796 existed as Pskov Viceroyalty) was established. Catherine the Great incorporated it as a town in 1777.
On August 1, 1927, the uyezds were abolished, and Ostrov became the administrative center of Ostrovsky District. The governorates were abolished as well, and the district became a part of Pskov Okrug of Leningrad Oblast. On July 23, 1930, the okrugs were also abolished, and the districts were directly subordinated to the oblast. Between March 22, 1935 and September 19, 1940, Ostrovsky District was a part of Pskov Okrug of Leningrad Oblast, one of the okrugs abutting the state boundaries of the Soviet Union. Between August 1941 and July 1944, Ostrovsky District was occupied by German troops. An underground resistance group was active in Ostrov during the war. On August 23, 1944, the district was transferred to newly established Pskov Oblast.