Istanbul Airport has become the world’s most internationally connected airport for the first time, overtaking London Heathrow in OAG’s Megahubs 2026 ranking. The result places Istanbul at the top of a global hub market increasingly defined not simply by passenger capacity, but by how efficiently airlines and airport schedules connect travellers between different regions. Istanbul recorded a connectivity index of 265.4, the highest among the 201 airports analysed by OAG. The airport generated 89,456 potential international connections across 337 destinations, moving up from second place in 2025.
The ranking is based on the number of possible connections between arriving and departing international flights within a six-hour window, measured against the number of destinations served. This means the index does not simply reward airports with the most passengers or flights. It measures how effectively an airport’s schedule allows passengers to connect from one service to another. That distinction is particularly important in Istanbul’s case. The airport ranked eighth globally by seat capacity during the period covered by the study, yet finished first for international connectivity. Its network structure therefore allows it to generate a greater level of connecting opportunity than several airports operating with higher overall capacity.
Turkish Airlines plays a central role in that structure, accounting for approximately 80 percent of capacity at Istanbul Airport. The carrier’s network stretches across Europe, Asia, Africa, the Middle East and the Americas, allowing Istanbul to function as a transfer point between regions that would otherwise require multiple connections through different hubs. The result also reinforces Istanbul’s position in a global competition where airport size alone is no longer enough. For airlines, passengers and destinations, the value of a hub increasingly depends on how many markets can be connected through a coordinated schedule rather than simply how many seats pass through the terminal.
Heathrow Falls to Second Place
London Heathrow, which led the 2025 ranking, moved into second position with a connectivity index of 246.2. The airport generated 55,888 potential connections across 227 destinations. OAG reported that Heathrow’s potential connections on the busiest day of the year declined by 6 percent compared with 2025. Disruption to Middle East schedules was one of the factors behind the decline, with Heathrow’s capacity to the region falling by around 25 percent year-on-year in August.
Amsterdam Schiphol retained third place with a connectivity index of 242.7, supported by 68,189 potential connections across 281 destinations. Kuala Lumpur remained fourth, while Chicago O’Hare moved into fifth place. The differences between the leading hubs highlight how connectivity can shift even when airport infrastructure remains largely unchanged. Airline network decisions, geopolitical disruptions, schedule coordination and capacity restrictions can all alter how effectively a hub connects international markets.
Connectivity Becomes a Competitive Advantage
For major hub airports, international connectivity has implications beyond aviation. A well-connected airport strengthens a city’s accessibility for corporate travel, international congresses, exhibitions and major events. The number of direct destinations matters, but the ability to connect delegates from secondary markets through a single hub can be equally important when organisers evaluate destinations. This gives Istanbul an advantage that extends beyond point-to-point traffic.
A congress delegate travelling from Central Asia to Europe, from Africa to the Balkans or from East Asia to Latin America can potentially use Istanbul as a single transfer point. The broader and more coordinated that network becomes, the more useful the airport is for international events drawing participants from multiple regions. For MICE destinations, this type of connectivity can directly affect bidding competitiveness. Organisers increasingly evaluate not only venue capacity and hotel inventory, but also the number of direct and one-stop connections available to delegates.
Istanbul’s Hub Model Depends on Network Coordination
Istanbul’s position at the top of the ranking is closely linked to the concentration of Turkish Airlines operations at the airport. With approximately four-fifths of capacity controlled by a single carrier, flight schedules can be structured around coordinated arrival and departure waves that create large numbers of transfer opportunities. This differs from airports where capacity is distributed more evenly among multiple airlines with less integrated schedules.
The model also helps explain why Istanbul can outperform larger airports in connectivity despite handling fewer seats. The value of the hub comes not only from scale, but from how that scale is organised. As global aviation capacity continues to shift between regions, the next stage of hub competition is likely to focus increasingly on this efficiency. For Istanbul, reaching the top of the Megahubs ranking marks a new stage in that competition. The airport is no longer competing only on the breadth of its network or the growth of Turkish Airlines, but on how effectively those two elements work together to connect global traffic.
