The Dormition or Assumption Church (Успенська церква) is the main Orthodox church in the city of Lviv, Ukraine. At present it is leased to the Ukrainian Autocephalous Orthodox Church. It was constructed in the late 16th and early 17th centuries with funds provided by the Greek merchant Constantine Corniaktos and other members of the Lviv Dormition Brotherhood, a local bratstvo which also operated a well-known Orthodox school and press.
The church's architecture bears the mark of the Renaissance. This especially applies to the profusely decorated façade of the adjacent Chapel of the Three Hierarchs, built between 1574 and 1591 to Piotr Krasowski's designs. Nearby is one of Lviv's most conspicuous landmarks, the Korniakt Tower, which was carried to its present height of 65 meters after a conflagration in 1695. This ornate bell-tower was originally commissioned by Corniaktos from architect Piotr Barbon in the 1570s.