The world’s busiest domestic route was Jeju-Seoul in the Republic of Korea, carrying 13.3 million passengers. It was followed by Japan’s Sapporo-Tokyo and Fukuoka-Tokyo routes, with 9.6 million and 9.5 million passengers, respectively. Vietnam’s Hanoi-Ho Chi Minh City route ranked fourth with 8.9 million passengers.
By comparison, the busiest domestic route in the US, New York-Los Angeles, carried 2.2 million passengers in 2025, while Europe’s Barcelona-Palma de Mallorca route recorded 2.1 million.
According to IATA’s ranking of global air passenger markets, the US remained the world’s largest market in 2025, with 890.1 million passengers, up 1.6% from 2024. China, the world’s second-largest market, recorded stronger growth of 4.8%, reaching 776.1 million passengers. China is widely forecast to overtake the US and become the world’s largest air passenger market in the 2030s.
The UK ranked third, followed by Spain and Japan.
IATA compiled the data from 1,315 airlines worldwide. Observers said the figures underscore continued strong demand for air travel across many markets, with Asia playing an increasingly important role in the global aviation landscape./.
