Heathrow loses Europe’s busiest airport crown to Istanbul as third runway push grows

London Heathrow Airport (LHR) has restated that “the case for expansion has never been clearer” after it was revealed that the West London gateway had lost the crown as Europe’s busiest airport to Istanbul.

Figures published on 11 August by aviation data firm OAG showed that Heathrow Airport handled 7.86 million passengers across its four terminals in July, traditionally the airport’s busiest month of the year. However, Istanbul Airport (IST) in Turkey handled 8.15 million passengers during the same month, surpassing the London facility by almost 300,000 passengers.

The UK’s biggest airport, located west of central London, previously held the position as Europe’s busiest airport from 1996 until 2019, when it was dislodged from the top of the table due to COVID-19 travel restrictions. The airport regained the crown in 2023, which it has held since.

Notably, Heathrow’s July passenger total was down 1.5% compared with the same month in 2025, while Istanbul saw a 2.3% increase in passenger numbers. The airport put this down to the impacts of the US-Iran War affecting traffic numbers to the United States as well as disruption to flights heading to the Middle East.

As reported by The Guardian, the airport’s passenger numbers on Middle East routes were down 20.2% in July compared to the same month last year.

Heathrow Airport calls for further expansion to be approved

Notwithstanding the blow of being displaced by Istanbul for traffic numbers, Heathrow Airport is remaining bullish about the future and is using the situation to strengthen its case for further expansion.

Heathrow continues to operate its two runways at near full capacity and is seeking UK government permission to build a third, enabling the airport to handle 150 million passengers a year. It handled a record 84.46 million passengers in 2025.

“Heathrow is operating at capacity, and the case for expansion has never been clearer,” said a spokesperson for Heathrow Airport. “Our plans will ensure the country gets the infrastructure it needs to stay competitive and will deliver all-important economic growth.”

The UK’s transport secretary, Heidi Alexander, launched a consultation on the renamed Heathrow expansion national policy statement in June, setting out the conditions needed if the project is to be given the go-ahead. The new UK Prime Minister, Andy Burnham, has previously expressed concerns over further expansion at Heathrow, stating the plans would divert infrastructure investment away from other regions of the UK.

In the meantime, Heathrow enjoyed its busiest day of 2025 so far on 19 July when 267,000 passengers passed through the airport. Additionally, several airlines have begun operating new services from the airport this summer, including British Airways, ITA Airways, Alaska Airlines, and Riyadh Air.

The Heathrow chief executive, Thomas Woldbye, said that despite the busy summer season underway, the airport wanted to “go further, growing our route network and passenger offering. Expanding Heathrow will help ensure the UK remains home to Europe’s leading hub and continues to benefit from the trade, investment and tourism that increased connectivity will bring.”