Uspenskin Cathedral is a Russian Orthodox cathedral located in Helsinki, Finland. It was built between 1862 and 1868 as a tribute to Tsar Alexander II of Russia and was designed by the Russian architect Aleksey Gornostayev. The cathedral was named after the icon of the Dormition of the Mother of God, also known as the Uspenski Cathedral.

The cathedral is situated on a hill overlooking the city and the harbor, and its distinctive red-brick construction and golden onion domes make it a notable landmark in the city skyline. Inside, the cathedral is decorated with intricate mosaics, frescoes, and ornate chandeliers.

Uspenskin Cathedral is the largest orthodox church in Western Europe, with the capacity to accommodate up to 5,000 people. It is an important center of worship for the Finnish Orthodox Church, which is part of the Ecumenical Patriarchate of Constantinople. The cathedral also serves as a cultural center, hosting concerts, exhibitions, and other events.

Visitors are welcome to explore the cathedral and its grounds, and guided tours are available. The cathedral is open daily, and admission is free. However, visitors are asked to dress appropriately and respect the religious significance of the cathedral.