Aviation revelation: the 10 most popular routes in 2025

And the journey with most passengers is... a domestic link in South Korea, from a secondary airport

- Simon Calder

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.