Uspenski Cathedral (Finnish: Uspenskin katedraali, Swedish: Uspenskij-katedralen, Russian: Успенский собор) is an Eastern Orthodox cathedral in Helsinki, Finland, dedicated to the Dormition of the Theotokos (the Virgin Mary). Its name comes from the Old Church Slavonic word uspenie, which denotes the Dormition. Designed by the Russian architect Alexey Gornostaev (1808–1862), the cathedral was built after his death in 1862–1868.
The crypt chapel of the cathedral is named after the holy Alexander Hotovitzky, who served as vicar of the Orthodox parish of Helsinki 1914–1917.
The Cathedral is set upon a hillside on the Katajanokka peninsula overlooking the city. On the back of the cathedral, there is a plaque commemorating Russian Emperor Alexander II, who was the sovereign of the Grand Duchy of Finland during the cathedral's construction. Main cathedral of the Finnish Orthodox Church in the diocese of Helsinki, Uspenski Cathedral is claimed to be the largest orthodox church in Western Europe, although Finland is normally included into Northern Europe.
In 2006, about 516,500 tourists visited the church. Admission to the Cathedral is free of charge. In winter, the Cathedral is closed on Mondays.