The Saint Gregory the Illuminator Church of Galata (Armenian: Ղալաթայի Սուրբ Գրիգոր Լուսաւորիչ եկեղեցի, Ghalat’ayi Surp Krikor Lusavorich yegeghetsi; Turkish: Surp Krikor Lusavoriç Ermeni Kilisesi) is the oldest extant Armenian Apostolic church in Istanbul.

[3][5][a] According to a manuscript formerly kept at the Armash monastery the church was founded in 1391 by an Armenian merchant named Kozma (Italian: Cosimo) from Kaffa (now Feodosia) in Crimea who bought the land on which it was built.

It was restored 28 years later, in 1799 by the architect Minas Khalfa who added the chapel of Surb Karapet ("Holy Precursor", i.e. John the Baptist).

[5][9] The church was visited and described by European visitors such as Antoine Galland (1672),[1] Joseph Pitton de Tournefort (early 1700s),[10] and William Holden Hutton (c. 1900).

[12] The church was expropriated by the state and demolished in May 1958 to widen the street as part of large-scale reconstruction in Istanbul in the Adnan Menderes period.

Due to the limited space allocated for the church, a basement was built to house the chapel and the grave of Hovhannes Golod (below the bell tower) and a balcony for the choir.