Istanbul Airport has overtaken London Heathrow to become the world's most internationally connected airport, according to a report that also showed five of the top 10 global aviation hubs are in Europe.
Istanbul Airport climbed from second place in 2025 and claimed the top spot for the first time, the Megahubs 2026 report by global travel intelligence partner OAG said Wednesday.
Istanbul has possible connections to 337 global destinations, with national flag carrier Turkish Airlines operating 80% of flights at the airport.
Heathrow fell to second place, as potential connections on the busiest day fell by 6% year-over-year, partly reflecting the ongoing disruption to Middle East schedules, the report said.
Istanbul, meanwhile, recently overtook Heathrow as Europe's busiest airport by passenger numbers. Industry groups and officials, including the London hub's CEO himself, had been expecting that to happen this year or the next.
The OAG report showed Amsterdam Schiphol rounded out the top three as it achieved growth in both its connections and the destinations it served.
"The 2026 rankings reflect a global aviation landscape that is still recalibrating after significant disruption," said John Grant, chief analyst at OAG.
"Istanbul's rise to the top reflects the strength of Turkish Airlines' network and the airport's geographic position as a connecting hub between east and west," Grant noted.
The rankings are based on the number of possible connections between inbound and outbound flights within a six-hour window on the busiest day of the year, Sunday, Aug. 2, and the number of destinations served from the airport.
Selahattin Bilgen, CEO of Istanbul Airport operator IGA, said the achievement reflected their strategic development, together with the breadth and reach of Turkish Airlines' network.
"From the outset, IGA Istanbul Airport was designed to accommodate future expansion, supported by Istanbul's unique geographical position and our ever-growing airline network," Bilgen noted.
"As we continue to expand our global connectivity and enhance passenger experience, we remain committed to further strengthening Istanbul's position as one of the world's leading aviation hubs."
The gleaming glass-and-steel structure along the Black Sea coast has become one of the most important transit centers in aviation since it became fully operational in April 2019.
The hub can handle 90 million passengers a year in the current phase. The figure is nothing compared to its potential capacity to serve 200 million after completing all phases.
Istanbul Airport served a record-breaking 84.4 million passengers in 2025, making it the second-busiest airport in Europe after Heathrow and the eighth-busiest worldwide. It seeks to reach the 90 million mark this year.
Kuala Lumpur retained fourth position in the OAG ranking and remained the most connected airport in Asia as its served destinations increased to 154.
Chicago O'Hare rose from seventh in 2025 to fifth globally as the most connected airport in the Americas.
The Chicago airport increased its potential connections by 9.8% and expanded its destinations from 297 to 308 to achieve the third-widest international reach in the world, behind Istanbul with 337 destinations and Frankfurt with 310 destinations.
Other European hubs in the top 10 include Frankfurt International Airport in seventh and Paris Charles de Gaulle Airport in ninth.
The Asia Pacific region dominated the global top 20, accounting for eight of the 20 positions.
Chinese airports made notable gains as Shanghai Pudong rose from 19th to 14th, while Baiyun International jumped from 36th to 19th.
Hong Kong returned to the top 20 by moving from 22nd to 20th.
Kuala Lumpur ranked first in the Low-Cost Carrier Megahubs Index with nearly 15,000 possible low-cost connections.
The Asia Pacific region accounted for 64% of the top 25 low-cost airports.
Low-cost carriers represented 51% of all seats across Southeast Asia compared to a global average of 34%.