Coordinates: 54°46′N 38°53′E / 54.767°N 38.883°E / 54.767; 38.883

Zaraysk (Russian: Зара́йск) is a town and the administrative center of Zaraysky District of Moscow Oblast, Russia, situated about 162 kilometers (101 mi) southeast from Moscow. Population: 24,648 (2010 Census preliminary results); 25,093 (2002 Census); 26,958 (1989 Census).

The town stands on the right bank of the Osyotr River, which is a right confluent of the Oka. In the Middle Ages, the town belonged to the Princes of Ryazan and was known as Krasnoye (13th century) and Novogorodok-upon-the-Osetr (14th and 15th centuries). From 1528 onwards the town was called "the town of Nikola Zarazsky" and only by the beginning of 17th century it received its present name of Zaraysk. Before the 20th century the town was part of Ryazan guberniya, as its architecture and vernacular dialect seem closer to Ryazan than to Moscow.

In Muscovite Russia, Zaraysk was one of the fortresses forming a part of the Great Abatis Border, a fortified line of felled trees, barricades, fortresses, ditches, which were built by Russians as a protection against the hordes of the Crimean and Kazan Tatars. In 1531 a stone kremlin was built in place of the former wooden citadel. The Tatars failed to take the fortress during their raids in 1533, 1541 and 1570. It was briefly captured by the Lisowczycy during the Time of Troubles.