The Hagia Triada is a Greek Orthodox church in Istanbul, Turkey. The building was erected in 1880 and is considered the largest Greek Orthodox shrine in Istanbul today. It is still in use by the Greek community of Istanbul. It has about 150 parishioners. The church is located in the district of Beyoğlu, in the neighborhood of Katip Çelebi, on Meşelik sokak, near Taksim Square.