St. Theodosius Cathedral (Russian: Собор Святого Феодосия) is an Eastern Orthodox church located on Starkweather Avenue in the West Side neighborhood of Tremont in Cleveland, Ohio.

Considered one of the finest examples of Russian church architecture in the United States,[2] it is listed on the National Register of Historic Places.

[5] The cathedral is perhaps best known for its appearance in the 1978 Best Picture-winning film, The Deer Hunter, with Robert De Niro, Christopher Walken, and Meryl Streep.

[6] He established a small skete on the island of Mikhailovschino or Mikhailovschina in 1680 and, in 1688, he was appointed archimandrite of the Yeletskyi Dormition Monastery in Chernigov.

[2][4] The founders had emigrated from Carpathian Ruthenia in Austria-Hungary (now Zakarpattia Oblast in present-day Ukraine) when the tide of Eastern European immigration to the American urban centers of the Northeast and Midwest was at an all-time high.

This same situation played out in many Eastern Catholic parishes in the US, and the results formed the core group of the present Orthodox Church in America (OCA).

[2][4] The Russian Missionary Fund established by Tsar Nicholas II provided financial assistance.

After the February Revolution, the Russian Provisional Government abolished the Most Holy Synod and allowed the church to restore the Patriarchate.

The Soviet government opposed the church, and many White émigrés came to Cleveland and joined St. Theodosius during this period.

[19] The cathedral was built in a recognizable Neo-Byzantine style; a type of Russian church architecture with one large, four medium, and eight small copper onion domes, symbolic of Christ and the twelve apostles.

[2][4] The iconostasis, separating the sanctuary from the larger portion of the cathedral accessible to the faithful, contains the following icons imported from Russia:[2] In 1953, the church commissioned murals by noted Russian émigré fresco painter Andrej Bicenko.