The world’s busiest air route is a domestic link that connects an island off the coast of Korea with the older, secondary airport in the capital, Seoul. Seven airlines compete on the trip. Fares are so low that even booking just 48 hours ahead for a Christmas Day flight reveals a price of just £14 for the 75-minute, 280-mile journey. OAG, the global aviation analyst, has revealed the clear winner in passenger numbers for 2025: Seoul Gimpo to Jeju Island.
The route is extremely popular with Korean holidaymakers, with almost 40,000 seats available each day.
All of the top 10 links are domestic. Second, third and seventh places in the OAG table for 2025 all start/end at Tokyo’s main airport, Haneda. The route to Sapporo on Japan’s northern island of Hokkaido has just over 33,000 seats per day; Fukuoka has 31,000; Okinawa, in the far southwest, has 22,000.
Vietnam takes fourth place: Hanoi to Ho Chi Minh City has 30,000 daily seats. It is the busiest route worldwide that is not between a national capital and a city on an island.
The busiest route globally outside of East Asia connects Saudi Arabia’s two biggest cities: the capital, Riyadh, and the Red Sea port of Jeddah, with 27,000 seats per day. On 25 December there are 14 departures each way between midnight and 6am alone. Fares on the 530-mile route are widely available at £38 each.
Australia’s sole representative takes sixth place: Melbourne to Sydney, at nearly 25,000 seats per day. It is the highest-rated journey not to involve a national capital. The two cities are less than 450 miles apart, making them ripe for high-speed rail. Paris and Marseille, a similar distance apart, are connected by frequent trains; the journey takes around three hours.
India has a similar issue. In eighth place is the route between Delhi and Mumbai, with 21,000 seats per day. The two cities are separated by 700 miles.
Shanghai’s Hongqiao, another secondary gateway, completes the top 10. In ninth place, with 20,000 daily seats, is the link to Beijing; 10th is the route to Shenzhen in the south – close to Hong Kong – with 500 fewer seats.
The highest-scoring international route, Hong Kong to Taipei, is close to the top 10 with almost 19,000 seats per day.
In the rankings of domestic routes by continent, Africa and Latin America do much better than Europe and North America.
Outside of Asia, Australia and the Middle East, which make up the top 10, the highest rated domestic link is in Colombia, connecting Bogota and Medellin’s main airport, at Rionegro. The distance between the two airports is just 134 miles, with flights taking under an hour. The road journey is so onerous that buses take around 10 hours. Christmas Day flights are available for £37.
Next best continent: Africa, specifically Cape Town to Johannesburg, with almost exactly 15,000 daily seats.
North America’s highest-achieving route is not, surprisingly, in the US – but in Canada. The Toronto to Vancouver route has 10,000 seats available each day.
Europe comes in behind every other continent except Antarctica. The busiest route is between Barcelona and Palma, with 8,000 seats per day.
What explains the relatively low scores of Europe and North America? The OAG study looks at airport-to-airport routes rather than city-to-city. For example, London to Milan is served by five UK airports and three in Italy. Similarly, passengers from New York to Chicago can choose from JFK, La Guardia and Newark, travelling to Midway or O’Hare.
The busiest US domestic link is New York JFK to Los Angeles International, with 9,400 seats per day.
The top 10 busiest air routes in 2025
- Seoul Gimpo-Jeju (Korea)
- Tokyo Haneda-Sapporo (Japan)
- Tokyo Haneda-Fukuoka (Japan)
- Hanoi-Ho Chi Minh City (Vietnam)
- Riyadh-Jeddah (Saudi Arabia)
- Melbourne-Sydney (Australia)
- Tokyo Haneda-Okinawa (Japan)
- Delhi-Mumbai (India)
- Shanghai Hongqiao-Beijing (China)
- Shanghai Hongqiao-Shenzhen (China)
Source: OAG
Read more Plane and Train Talk from Simon Calder here
