Istanbul still has active churches from six Christian traditions, and the practical question for a visitor is rarely which ones are famous. It is which ones you can walk into, which have become mosques, and which open only for a Sunday liturgy. This guide sorts the city’s churches by the community that built them and says, for each one, what it is today.
What is on this page
The City That Was the Capital of Eastern Christianity
As Byzantium and later Constantinople, this city was the spiritual centre of Eastern Christianity for more than a thousand years. It held the seat of the Ecumenical Patriarch, hosted the councils that settled what the early church believed, and filled its hills with basilicas.
The Ottoman conquest did not end that. Greek Orthodox, Armenian Apostolic, Syriac, Catholic and Protestant communities all kept building, on both the European and the Asian side, and their churches are still standing and in many cases still in use. What follows is those churches, grouped by tradition. If the question you came with is the difference between Catholic and Orthodox, that is a separate question and we answer it separately. If you would rather walk a handful of them with someone who can read the iconography, that is our Istanbul Christian sites day.
Three things a church here can be. Some are still churches with regular services. Some were converted to mosques and are visited as mosques today, Hagia Sophia and Chora among them. A few are museums or archaeological sites. The status of a building can change, so this page says what each one is rather than what it once was. Beyond the ones below we also wrote up five lesser-known churches worth the detour.
How Many Churches Does Istanbul Actually Have?
Nobody publishes a current count of church buildings in this city, and the numbers that circulate online trace back to a census taken in 2000. What is on the public record is the institutions behind them. The Turkish Directorate General of Foundations lists 167 community foundations still in activity, and that register is very largely a roll of Greek Orthodox, Armenian and Syriac congregations, named one by one, together with the churches, schools and hospitals they hold.
The buildings outnumber the congregations, and that is the real story of Christian Istanbul. In the city the Orthodox world once looked to, the 2023 US State Department religious freedom report counts fewer than 2,500 ethnically Greek Orthodox people left in Türkiye as a whole. So a church that looks shut is usually not abandoned; it is serving a parish counted in hundreds.
A church here can be shut on a Tuesday and full on a Sunday. The building tells you nothing about whether anyone still prays in it.
What that means for a visit: the famous buildings are easy, and the living ones take a little planning. A working parish may open only around its liturgy, and the liturgy may be the only hour that week when the doors are unlocked.
Which Churches Can You Go Into, and What Are They Now?
| Church | Tradition | What it is today | Going in |
|---|---|---|---|
| Hagia Sophia | Byzantine, then Orthodox | Working mosque since 2020 | Open, mosque rules, mosaics still visible |
| Chora (Kariye) | Byzantine Orthodox | Working mosque since 2024 | Open, mosque rules, fresco cycle intact |
| Hagia Irene | Byzantine, 4th century | Monument and concert hall | Open with a ticket, never a mosque |
| St. George, Fener | Greek Orthodox | Seat of the Ecumenical Patriarch | Open daily, active liturgy |
| St. Mary of the Mongols | Greek Orthodox | Parish church, never converted | Ring the bell, small parish |
| Aya Triada, Taksim | Greek Orthodox | Largest Greek Orthodox church in the city | Open, easiest Orthodox visit |
| Surp Asdvadzadzin, Kumkapı | Armenian Apostolic | Seat of the Armenian Patriarchate | Sunday services and feast days |
| St. Anthony of Padua | Latin Catholic | Largest Catholic church in Istanbul | Open daily on İstiklal |
| St. Stephen of the Bulgars | Bulgarian Orthodox | Cast iron church, restored | Open, on the Golden Horn |
Opening hours move with the church calendar and with restoration work, so treat this as the shape of the day rather than a timetable. Checked September 2026.
Greek Orthodox Churches
Istanbul keeps more Byzantine-founded churches than any other city, and the smallest congregation of any tradition here to fill them. Some were converted into mosques after 1453, others never were and still hold Orthodox worship.
- Hagia Sophia – built in 537 under Justinian and the seat of the Eastern Orthodox church for nearly a thousand years. A mosque again since 2020; its Christian mosaics are still visible.
- Chora (Kariye Mosque) – the finest mosaic and fresco cycle in the city, from the early fourteenth century. Reconverted to a mosque, and the art is still there.
- Church of St. Mary of the Mongols (Fener) – the only Byzantine church in Istanbul never converted into a mosque, and an active Greek Orthodox parish to this day.
- Church of St. George (Fener) – the seat of the Ecumenical Patriarch of Constantinople. Open, and it holds regular Orthodox services.
- Hagia Irene – one of the earliest churches of the city, inside the first courtyard of Topkapı. Never converted to a mosque; used today as a concert hall and a monument.
- Aya Triada (Taksim) – among the largest Greek Orthodox churches in the city, with a big dome and twin bell towers. Open and easy to visit.
- Panagia Isodion (Galata) – a historic Orthodox church still in use.
- Little Hagia Sophia – sixth century, older than its famous namesake, and a working mosque with its Byzantine columns and inscription intact.
One Byzantine church in this city has never once been a mosque. It is small, it is in Fener, and it has held the same liturgy since the thirteenth century.
Armenian Apostolic Churches
Armenians are the largest Christian minority, about 90,000 across Türkiye and concentrated here, and their churches trace an unbroken presence. We run an Armenian heritage day through them, and Ahmet Faik Özbilge, who wrote a book on Fener, Balat and Ayvansaray, knows this group best.
- Patriarchal Cathedral of Surp Asdvadzadzin (Kumkapı) – the seat of the Armenian Patriarchate of Istanbul. Open for Sunday services and feast liturgies.
- Surp Krikor Lusavoriç (Topkapı) – the oldest Armenian church in the city, founded in 1360 and rebuilt several times since.
- Surp Vartanants (Feriköy) – a modern and active parish serving the northern districts.
- Surp Pırgiç Hospital Church (Yedikule) – attached to the Armenian hospital, serving patients and the parish together.
- Surp Agop (Pangaltı) – active, and the interior repays the walk up.
Catholic Churches
The Latin Catholic community here is both Turkish and expatriate, about 25,000 nationwide, and its churches run from Venetian Gothic to plain working parishes with mass in four languages.
- St. Anthony of Padua (İstiklal Street) – the largest Catholic church in Istanbul, Venetian Gothic, active, and the easiest one to walk into.
- Saints Peter and Paul (Galata) – among the oldest Latin Catholic foundations in the city, going back to the fifteenth century.
- St. Mary Draperis (Beyoğlu) – eighteenth century, built over the ruins of a Byzantine church, with masses in several languages.
- Santa Maria (Kadıköy) – the main Catholic church on the Asian side.
- St. Stephen (Yeşilköy) – the parish for this seaside neighbourhood near the old airport.
- Franciscan Church of St. Maria (Karaköy) – a simple, active parish with services in English and Italian.
Protestant and Evangelical Churches
Smaller in number, 7,000 to 10,000 nationwide, and split between congregations serving foreign residents and Turkish-speaking ones.
- Dutch Chapel (Beyoğlu) – inside the Dutch consulate compound, with services in English.
- Union Church of Istanbul (Beyoğlu) – interdenominational and English-speaking.
- Anglican Christ Church (Kadıköy) – a historic Anglican church, services in English.
- Istanbul Protestant Church Foundation – Turkish-speaking congregations with churches in Kadıköy, Şişli and Beyoğlu.
Syriac and Other Eastern Churches
These communities trace their line to the first Christian centuries, and their liturgical language is closer to what Jesus spoke than anything else in the city. About 25,000 Syriac Orthodox remain in Türkiye. We wrote about the Syriac Orthodox community separately.
- St. Mary Syriac Orthodox Church (Tarlabaşı) – the active church of the small Syriac community.
- Chaldean Church of the Sacred Heart (Beyoğlu) – serving Iraqi Christians and other Eastern Rite Catholics.
- Georgian Church of St. Nicholas (Karagümrük) – what remains of a community that has now vanished from the city.
- St. Stephen of the Bulgars (Balat) – the cast iron church on the Golden Horn, prefabricated in Vienna and shipped down the Danube.
Churches Elsewhere in Türkiye
Several of the oldest and most significant churches in Türkiye are nowhere near Istanbul, and they are the reason people extend a city break into a circuit. The Seven Churches of Revelation are the usual reason.
- Church of St. Peter (Antakya) – carved into the mountainside, and among the oldest Christian places of worship anywhere.
- Basilica of St. John (Ephesus) – the ruins of the great basilica Justinian raised over the apostle’s tomb.
- House of the Virgin Mary (near Ephesus) – a pilgrimage site for Catholics and Muslims alike.
- Akdamar (Lake Van) – a tenth-century Armenian church on an island, its exterior carved with the whole of the Old Testament.
- Sümela Monastery (Trabzon) – an Orthodox monastery built into a cliff face above the Black Sea forest.
- Smyrna and Thyatira – two of the seven churches of Revelation, now in İzmir and Akhisar.
- Cave churches of Cappadocia – dozens of rock-cut chapels with their frescoes intact.
- Sardis (Manisa) – a synagogue and church complex on one site, and another of the seven churches of Revelation.
None of these is a day trip from Istanbul. Ephesus is an hour by plane and then an hour by road, Sümela means a flight to Trabzon, and Akdamar is most of a day out from Van. People who want the Seven Churches usually give the whole trip a week or more, and fly between the legs rather than drive them.
The Guides Who Studied This
A church is easy to photograph and hard to read. Two of our licensed guides have spent their working lives on exactly this material.
Ebru Gökteke specialises in Byzantine history, Christian iconography and Greek Orthodox heritage. She pursued graduate work in the History of Religions at Marmara University, and also completed an MA in Art History at Istanbul University, specializing in Christian iconography. She also gives seminars and public talks on subjects such as Early Christianity, the origins of Christmas, the Varangian Guards, and the Chora Church and its iconography.
Ahmet Faik Özbilge wrote the book on the church neighbourhoods of the Golden Horn. He guides tours in Istanbul’s offbeat neighborhoods all the time and he has intimate experience with many Greek and Armenian churches as well as synagogues like the Ahrida in Balat.
See them in one day
Istanbul Christian Sites Tour
Hagia Sophia, the mosaics of Chora, the Patriarchate and the church streets of Fener and Balat, in one private day with a guide who knows the iconography.
Questions Visitors Ask
Which churches in Istanbul can you go inside?
Most of them. St. Anthony of Padua on İstiklal, Aya Triada in Taksim, St. George in Fener and the Armenian cathedral in Kumkapı are all open to visitors outside service times. Hagia Sophia and Chora are entered as mosques, with the usual dress and shoe rules. A few of the smaller parish churches open only around a service.
Is Hagia Sophia still a church?
No. It was a church for nearly a thousand years, a mosque after 1453, a museum from 1935, and a working mosque again since 2020. You can go in, and the Christian mosaics that survive are still visible. The same pattern applies to Chora, which reopened as a mosque with its fresco cycle intact.
Can you attend a Christian service in Istanbul?
Yes, and visitors are welcome at most of them. There are Sunday services in Greek, Armenian, Turkish, English, Italian and Arabic across the city. Times shift with the church calendar, so it is worth confirming the week you travel rather than relying on a posted schedule.
Do you need a guide to visit Istanbul's churches?
Not to get in. You need one to understand what you are looking at: an icon screen, a donor portrait, the reason a Greek parish sits next to an Armenian one. That is the difference between a photograph and a day you remember, and it is what our Christian sites day is for.
How many days do you need for the churches outside Istanbul?
The Seven Churches of Revelation and the council cities are a separate trip, not a day out from Istanbul. We set that out honestly on the ten-day route page, including the shorter versions that work if you have less time.
Are there still Greek and Armenian Christians in Istanbul?
Yes, and far fewer than the buildings suggest. The 2023 US State Department report puts the ethnically Greek Orthodox population of Türkiye at fewer than 2,500, in the city that was once theirs. Armenians are the largest Christian minority at about 90,000. Both still hold regular liturgies, which is why some of the smaller churches open only around a service.
Which is the oldest church in Istanbul?
Hagia Irene is the usual answer. It stands in the first courtyard of Topkapı on a fourth-century foundation, and it is the one major Byzantine church in the city that was never converted into a mosque. The oldest church still serving its own congregation is a different question: St. Mary of the Mongols in Fener has held Orthodox worship without interruption since the thirteenth century.
What should you wear to visit churches in Istanbul?
For a church, ordinary clothes are fine. For Hagia Sophia and Chora, which are mosques now, you need shoes off and shoulders and knees covered, and women cover their hair. Carrying a scarf saves the queue for the ones handed out at the door. Visits pause during prayer times.
See These Churches With Someone Who Can Read Them
Tell us which traditions interest you and how long you have. We reply within a day with a route, the licensed guide who would walk it with you, and what is open on your dates. If you want to check us first, our reviews are there.
Tell us your dates. We reply within a day.
