The shift ends Heathrow’s latest reign at the top of the European rankings, a position it had held since regaining the crown in 2023 after the pandemic disruption. The west London hub had been Europe’s busiest airport in most years since 1996, losing the title only once before — in 2020, when coronavirus travel restrictions slashed demand across the continent.
Why Heathrow Lost the Top Spot
A 20.2% year-on-year drop in Middle East routes weighed on Heathrow’s July passenger numbers. The airport attributed the decline to the US-Israel conflict with Iran, which has disrupted one of its key long-haul markets. Istanbul, by contrast, has continued to expand its network across Asia, the Middle East, and Africa, positioning itself as a connecting hub between continents.
Heathrow still recorded 84.46 million passengers across 2025, and 19 July marked its busiest single day of the year so far, with 267,000 travelers passing through its four terminals as UK schools broke up for summer. Several new airlines began serving the airport last month, which the operator said demonstrates “clear demand for access to Heathrow.”
Capacity Crunch Drives Expansion Push
Heathrow’s two runways are operating at near-full capacity, leaving little room to absorb the growth that would help it reclaim the top ranking. The airport’s owners are seeking government permission to build a third runway, a project that would allow it to accommodate up to 150 million passengers per year.
In a statement, Heathrow said “the case for expansion has never been clearer,” adding: “Our plans will ensure the country gets the infrastructure it needs to stay competitive and will deliver all-important economic growth.”
Last month, regulators confirmed Heathrow will be allowed to charge airlines more to recover money spent on the early stages of its third runway project — a move that will push ticket prices up by around 15p per passenger as the costs are passed through.
What Happens Next
The July figures are a single-month snapshot, not a full-year ranking, and Heathrow could still finish 2025 as Europe’s busiest airport overall. But the data signals a structural challenge: Istanbul’s newer infrastructure and geographic advantage as an east-west connector give it headroom that Heathrow simply does not have under current runway limits. Watch the August and September numbers — if Istanbul extends its lead through the peak summer season, pressure on the UK government to approve Heathrow’s third runway will intensify. Meanwhile, Middle East route recovery will be the swing factor that determines whether Heathrow reclaims the top spot or cedes it for longer.
— Elena Petrov, travel desk, AXO News