Quick answerIstanbul is the largest city of Turkey, with 15,754,053 people inside the city limits in 2025. It is best known for the Hagia Sophia, the Blue Mosque and the Bosphorus. Its official language is Turkish, and its currency is the Turkish lira.
Istanbul is the largest city in Turkey, with 15,754,053 people (31 December 2025). It stands on both sides of the Bosphorus, in Europe and Asia, and is home to the Hagia Sophia, the Blue Mosque and Topkapı Palace.
Key facts
| Country | Turkey |
|---|---|
| Population (city) | 15,754,053 (2025) |
| Time zone | Europe/Istanbul |
| Language | Turkish |
| Currency | Turkish lira (TRY, ₺) |
| Coordinates | 41.01361° N, 28.955° E |
Overview
Istanbul is the largest city in Turkey, with 15,754,053 people at the end of 2025, and one of the largest cities in Europe. It stands in north-western Turkey, on both sides of the Bosphorus, the strait that joins the Black Sea to the Sea of Marmara — the only major city in the world that lies on two continents. About two-thirds of its people live on the European side and the rest in Asia.
Istanbul was founded as Byzantium in the seventh century BC, refounded as Constantinople in AD 330, and served as the capital of the Roman, Byzantine and Ottoman empires for nearly sixteen centuries. The Ottomans took the city in 1453. Its historic centre is a UNESCO World Heritage Site, and its best-known sights are the Hagia Sophia, the Blue Mosque, Topkapı Palace and the Grand Bazaar.
Today Istanbul is Turkey's economic, cultural and historical centre, producing about 30 per cent of the country's economy. It is home to two international airports, many universities and the headquarters of Turkey's largest companies, and in 2025 it was ranked the fifth most visited city in the world.
What Istanbul is known for
- Hagia Sophia
- Blue Mosque
- Bosphorus
- Grand Bazaar
- Two continents
- Topkapı Palace
Landmarks
- Hagia Sophia
- Blue Mosque
- Topkapı Palace
- Grand Bazaar
- Galata Tower
- Basilica Cistern
- Dolmabahçe Palace
Frequently asked questions
What is the population of Istanbul?
About 15.8 million people live in Istanbul (15,754,053 at the end of 2025, according to TurkStat). That is about 18 per cent of Turkey's whole population. The urban area alone has about 15.4 million people, making Istanbul one of the largest cities in Europe and the world.
Where is Istanbul and what is it known for?
Istanbul is in north-western Turkey, on both sides of the Bosphorus between the Black Sea and the Sea of Marmara. It is famous for the Hagia Sophia, the Blue Mosque, Topkapı Palace, the Grand Bazaar and the Galata Tower, and for being a city on two continents.
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Keep exploring
- Turkey — the country Istanbul is in
- Ankara — another city in Turkey
- Izmir — another city in Turkey
- Bursa — another city in Turkey
- All cities in Turkey
- All countries — the full list
Sources & last updated
- Wikipedia — Istanbul
- TurkStat, via Wikipedia — Istanbul (Address Based Population Registration System, 31 December 2025)
Last updated: . Figures are shown with their year; where sources disagree, the value is left out rather than estimated.