St. Theodosius Cathedral in Cleveland is the oldest Orthodox church in Ohio and is listed on the National Register of Historic Places in the USA. It belongs to the Midwest and Chicago Diocese of the Orthodox Church in America.

The history of the parish begins with the Society of St. Nicholas, established in 1895 on the advice of Father Ioann Kochurov. It included 23 Rusyns who converted to Orthodoxy from a Uniate parish. The official registration of the Society took place on September 28, 1896.

In the same year, a small building was constructed at the intersection of Literary Road and West 6th, where on October 19, Bishop Nikolai (Ziorov) consecrated the church in honor of St. Theodosius of Chernigov. Soon after, a church school was opened at the parish.

In 1902, the parish purchased land from the Augustinian sisters for $30,000, which was the site of the St. Joseph's convent. Streets named St. Olga and St. Tikhon were laid out on this land, and 80 lots were sold to parishioners. The building at Starkweather, 64 housed the church, school, and the priest's apartment. On the third floor was a boys' school known as the 'Bursa.'

By 1905, the parish had 15 families. In 1909, land was purchased for a cemetery in the Brooklyn area. By 1910, the church building became cramped for all parishioners.

On September 23, 1911, the foundation of a new stone church was laid according to the design of Frederick Baird. $70,000 was raised for its construction, including a donation from Nicholas II. The full consecration of the cathedral took place on July 20, 1913, by Bishop Alexander (Nemolovsky).

In the 1930s, the cathedral choir became well-known throughout Cleveland, performing at the art museum and attracting many listeners. In 1936, the Fifth All-American Church Council was held here, and in 1946, the historic Seventh Council.

In 1953, a Sunday school was opened, and the parish had 1,200 families. In 1950, the reconstruction of the cathedral began, which was completed on October 3, 1954. From the late 1950s, services began to be conducted in English alongside Church Slavonic.

By 1974, the number of parishioners had decreased to 600 families, but the church remained an important cultural center. In 1980, an exhibition of Russian art was held here.

In the early 2000s, the cathedral was restored and re-consecrated in September 2001 by Metropolitan Theodosius.

The cathedral building is designed in a pseudo-Byzantine style with a large dome and 12 smaller ones. It is considered a model of Russian church architecture in the USA and is based on the Cathedral of Christ the Savior in Moscow.

Icons for the cathedral were brought from Russia. The iconostasis features images of St. Nicholas the Wonderworker, Archangel Michael, the Most Holy Theotokos, the Savior, Archangel Gabriel, and St. Theodosius of Chernigov. The middle row includes the Last Supper and saints, the upper row, the Holy Trinity and the 12 apostles, and at the top, the Crucifixion with the Most Holy Theotokos and John the Baptist.

The frescoes of the church were painted in 1950 and 1954 by Yugoslav artist Andrei Bicenko. The cathedral gained worldwide fame after the release of the film 'The Deer Hunter' in 1978, where it appeared in several scenes.