Church of the Blessed Virgin Mary's Immaculate Conception, Roman Catholic temple in Baku, Azerbaijan

The Church of the Blessed Virgin Mary's Immaculate Conception was a Roman Catholic church in Baku, built in 1912 by Polish architect Józef Płoszko in a pseudo-Polish Gothic style. Its main facade had a two-tower composition with faceted, open-type towers topped by crockets, and included a portal and a rose window. The church was demolished in 1935; the Culture Center of the State Security Service now stands on its site.

Baku's Catholic community, led by Georg Mayer, first requested land for a church in 1883, but funds ran short and the plot went to the Orthodox Alexander Nevsky Cathedral. A new plot was granted on 23 December 1891; a parish house and chapel followed in 1894. Józef Płoszko designed the church, construction began in 1908, and it was completed in 1912, serving until 1935, when it was demolished.

The church was long called "the Polish church" because its main donors and parishioners were Poles, among them the Rylski oil family and Witold Zglenicki. Its pastor Stepan Demurov was arrested in November 1937 and sentenced to death in February 1938. A new church of the same name was consecrated in 2006.

The church stood at the corner of Merkuryevskaya (now Zarifa Aliyeva Street) and Caspian (now Rashid Behbudov Street) streets, a location considered prestigious. Nothing of the building survives: since 1948 the site has been occupied by the Culture Center of the State Security Service, formerly the Dzerzhinsky Palace of Culture, designed by Hasan Majidov. A new Church of the Immaculate Conception was built elsewhere in Baku in 2006.

The church was never rebuilt: it was demolished in 1935, and the Culture Center of the State Security Service (1948, architect Hasan Majidov) now stands on the site at the corner of the former Merkuryevskaya and Caspian streets. Its last pastor, Stepan Demurov, was arrested in November 1937 and sentenced to death in February 1938.