Istanbul Airport has overtaken London Heathrow to become the world’s most connected airport in OAG’s 2026 Megahubs ranking, ending Heathrow’s run at the top. The result places Istanbul first for global connectivity, with Turkish Airlines operating 80% of flights at the airport and 337 destinations reachable from the hub.
OAG based the ranking on possible connections within a six-hour transfer window on the busiest day of the year, Sunday 2 August, rather than on passenger traffic alone. Istanbul posted a connectivity index of 265.4 and 89,456 potential connections, while Heathrow slipped to second with an index of 246.2 and 55,888 potential connections.
The shift reflects Istanbul’s growing role as a transfer point between Europe, Asia and beyond, supported by Turkish Airlines’ network scale. Heathrow’s potential connections fell 6% year on year, with disruption to Middle East schedules among the factors behind the decline. Istanbul had ranked second in 2025 before moving into first place in the latest study.