Istanbul Airport has reached the top of the global aviation connectivity rankings, overtaking London Heathrow to become the world’s most connected international airport for the first time.
The achievement comes from the OAG Megahubs 2026 ranking, which evaluates the strength of international airport networks by examining the number of potential flight connections available within a six-hour window and the number of destinations served. Istanbul Airport recorded a connectivity index of 265.4, placing it ahead of London Heathrow and Amsterdam Schiphol.
#1
OAG Megahubs 2026
265.4
Connectivity Index
337
Destinations Worldwide
89,456
Potential Connections on Peak Day
Istanbul vs. Heathrow
| OAG Megahubs 2026 | Istanbul Airport | London Heathrow |
|---|---|---|
| Rank | 1st | 2nd |
| Potential connections (peak day) | 89,456 | 55,888 |
| Destinations served | 337 | 227 |
OAG Megahubs 2026: Top 5
- 1Istanbul Airport
- 2London Heathrow
- 3Amsterdam Schiphol
- 4Kuala Lumpur International Airport
- 5Chicago O’Hare, the most connected airport in the Americas
How the Ranking Works
The ranking is based on scheduled international flights and destinations served between September 2025 and August 2026, with August 2, 2026 used as the year’s busiest day for global aviation. Rather than simply measuring passenger numbers, OAG’s methodology focuses on how effectively an airport functions as a transfer hub.
Istanbul’s Climb to the Top
- OAG Megahubs ranking 2024: 8th
- Rose sharply to second place, behind Heathrow 2025: 2nd
- Overtook Heathrow for the first time 2026: 1st
A Strategic Advantage Between Continents
Located between Europe and Asia and within relatively short flying distances of the Middle East and North Africa, Istanbul has developed into a major transfer point for passengers travelling between different regions of the world.
A significant share of passengers use the airport to connect between international destinations, so its importance extends beyond the number of people travelling to Istanbul itself.
The Turkish Airlines Effect
OAG identifies Turkish Airlines as the dominant airline at Istanbul Airport, operating around 80 percent of its capacity.
The airline’s broad network allows Istanbul to function not simply as a destination airport, but as a major transfer hub connecting markets that otherwise have limited direct links.
Busiest vs. Most Connected
Istanbul is not currently the world’s busiest airport by total passenger traffic. That distinction illustrates why passenger numbers alone do not determine an airport’s influence in the global aviation system.
8th
Busiest airport in the world in 2025 (ACI World), with about 84.4 million passengers
2nd
Busiest airport in Europe by passengers, narrowly behind London Heathrow
1,491
Average daily flights in 2025, Europe’s busiest for the fourth consecutive year (Anadolu Agency)
Heathrow Slips to Second
London Heathrow, which had topped the OAG connectivity ranking for three consecutive years, dropped to second place in 2026, although it remains one of the world’s most important international gateways.
OAG said Heathrow’s connectivity was affected partly by disruptions to Middle Eastern flight schedules. Potential connections at the airport fell by around 6 percent year-on-year, while scheduled capacity to the Middle East was also significantly lower.
Part of a Broader Transformation
Opened in 2018 and subsequently becoming the principal international hub of Turkish Airlines, Istanbul Airport was designed to accommodate continued growth in global air traffic. Its rise in connectivity has coincided with the expansion of Turkish Airlines’ global network and Istanbul’s increasing role as a bridge between major aviation markets.
The combination of location, infrastructure and an extensive airline network has created a powerful hub effect, signalling that Istanbul is no longer simply a major stop between Europe and Asia, but one of the world’s principal gateways for international air travel.
