Sergiyev Posad (Се́ргиев Поса́д) is a city and the administrative center of Sergiyevo-Posadsky District of Moscow Oblast, Russia. It grew up in the 15th century around one of the greatest of Russian monasteries, the Troitse-Sergiyeva (Trinity) Lavra established by St. Sergius of Radonezh. The town became incorporated in 1742. As the town's name, alluding to St. Sergius, had strong religious connotations, the Soviet authorities changed first to just Sergiyev in 1919, and then to Zagorsk in 1930, in memory of the revolutionary Vladimir Zagorsky. The original name came back into official use in 1991. According to the 2002 Census, the town had population of 113,581, down from 114,696 recorded in the 1989 Census.
Tourism associated with the Golden Ring plays a role in the regional economy. There is also an important factory of toys.
In 1947, the Soviet Union established its first factory to weaponize smallpox at the edge of Sergiyev Posad.
The Moscow - Yaroslavl railway and highway pass through the town. Sergiyev Posad Bus Terminal is located in the city.
