South Korean airport becomes busiest in world for global traffic amid Iran war

South Korea’s Incheon airport has become the world’s busiest airport for international passengers, in part owing to disruption in the Middle East caused by the Iran war.

The airport, South Korea’s main gateway, about 30 miles (48km) west of Seoul, handled 38.39 million international passengers in the first half of 2026, according to preliminary figures compiled by the Airports Council International (ACI), the global trade body for airports.

Heathrow in the UK was second, with 37.79 million, followed by Changi airport in Singapore with 34.53 million.

It is the first time Incheon has topped the international passenger rankings since opening in 2001. The airport was 10th in the world in 2002, rising to fifth in 2018 and third in 2024 and 2025.

Part of the increase was attributed to disruption caused by the US-Iran conflict, which weakened the role of Middle Eastern hubs such as Dubai and diverted some transfer traffic to alternative routes through east Asia, Incheon International Airport Corporation (IIAC) was quoted as saying by the Yonhap news agency.

Incheon’s international passenger traffic was up 6.3% year on year overall, with rising numbers of foreign visitors also contributing to the increase.

Foreigners accounted for 39.3% of Incheon’s passengers in the first half of the year, up from 35.2% for the whole of 2025. The proportion reached a record 44.4% in the second quarter, with IIAC attributing the increase largely to growing numbers of visitors from China and Japan, according to local media.

Heathrow, in west London, recorded 40 million passengers in total in the first half of the year, including both domestic and international travellers, its busiest first half on record. Passenger traffic to Asia-Pacific rose 7.9%, while capacity to the Middle East reportedly fell 16.5% owing to the regional conflict.

Earlier this week Istanbul overtook Heathrow as Europe’s busiest airport by total passenger numbers. Figures published on Tuesday showed 7.9 million passengers passed through Heathrow’s terminals in July, compared with Istanbul’s 8.15 million.

Incheon has also expanded its role as an international hub. It serves 101 airlines flying to 183 cities, including 158 international passenger destinations.

A four-phase expansion completed in late 2024 increased the airport’s annual capacity to 106 million passengers.

Kim Beom-ho, the acting president of IIAC, said the ranking reflected “the support of the government, the public’s encouragement and the hard work of everyone stationed at the airport”.

South Korea also lays claim to the world’s busiest air route. The domestic corridor between Gimpo airport and Jeju island had 14.4 million seats scheduled in 2025, according to the aviation data provider OAG, more than any other route in the world.

Reporting from The Guardian contributed to this story.