Istanbul surpasses London Heathrow as Europe’s busiest airport in 2025

“Today, Turkish Airlines has scheduled service to more than 350 destinations from Istanbul, making it the airline that serves the most destinations nonstop from a single airport. Its flights reach over 125 different countries, more than any other airline,” states the report.

Istanbul Airport’s infrastructure also plays a significant role in its growth. Opened in 2019 as a replacement for Atatürk Airport, it was designed as a large hub with room for expansion. Currently operating three runways—with plans for five by 2028—the airport can accommodate more flights than Heathrow, which still operates only two runways.

The airport’s phased development is ongoing. The current third phase will raise annual capacity to 120 million passengers by adding new terminals and runways along with a solar power plant intended to power the facility. By 2030 and beyond, completion of further phases could bring total capacity up to 200 million passengers per year.

Turkish Airlines’ international expansion continues at pace; this year alone it added new North American routes including Denver and Minneapolis and resumed or launched services to several cities emerging from conflict such as Damascus and Aleppo in Syria.

In addition to Turkish Airlines’ activities, non-Turkish carriers are expanding their presence at Istanbul Airport as well. Nearly half of almost forty new routes introduced in 2025 are operated by foreign airlines including Aegean Airlines (to Greek islands), Air Europa (Madrid), Air Transat (Toronto), All Nippon Airways (Tokyo Haneda), among others.

Another notable development is the growth of Sabiha Gokcen International Airport (SAW), located on the Asian side of Istanbul. SAW entered OAG’s top ten busiest European airports at number ten with an annual seat capacity increase of 19%. This growth is largely driven by low-cost carriers like Pegasus Airlines and AJet—Turkish Airlines’ subsidiary—which are expanding both domestically and internationally.

“Heathrow's historical dominance as Europe's busiest airport has been built on the diversity of the airlines that fly there... By contrast, Istanbul Airport is much more like Atlanta... A large carrier leverages its advantageous geographical position... But Istanbul doesn't benefit from the same carrier diversity,” notes the analysis.

With ongoing infrastructure projects and ambitious fleet expansion plans by Turkish Airlines and other operators based at both IST and SAW airports, Istanbul appears set to maintain its lead as Europe’s busiest air travel hub for years ahead.