The Armenian Catholic Archeparchy of Istanbul, also known as Armenian Catholic Archdiocese of Constantinople, serves Armenian Catholics in Turkey and is under the Armenian Catholic Patriarch of Cilicia. The seat is in Istanbul.
Originally established in 1860, the current archeparchy was erected 15 October 1928. On Saturday, 21 March 2015, it was made known that the Patriarch of Cilicia of the Armenians, with the consent of the Synod of Bishops of the Patriarchal Church, and after having informed the Holy See, had accepted the renunciation of the pastoral government of the Armenian Catholic Archeparchy of Istanbul, presented by Archbishop Hovhannes Tcholakian, in accordance with Canon 210 of the Code of Canon Law for the Eastern Churches. Pope Francis then terminated the office of Apostolic Administrator sede plena of the Armenian Catholic Archeparchy of Istanbul's Armenians, Mons. Boghos Lévon Zékiyan, thus making possible his election to the Office of Archbishop of Istanbul, made by the Synod of Bishops of the Patriarchal Church of Armenia.
The eparchy was the seat of the Armenian Catholic Patriarchate of Cilicia from 1866 until 1928, when the patriarchal seat was moved to Beirut, Lebanon.
In 2008 there were 3,650 Armenian Catholics belonging to the diocese.