Asia-Pacific dominated the 2025 world’s busiest airline routes, according to OAG’s annual report. Nine of the 10 busiest routes globally were in that region, with the South Korean domestic route Jeju to Seoul ranking first, with 14.4 million seats scheduled, up 1% year over year. The route, however, is still 17% under its capacity level in 2019, according to OAG. 

Following that route were two domestic Japanese routes: from Tokyo Haneda to Sapporo New Chitose ranking second and Tokyo to Fukuoka third. 

The sole Top 10 route outside of Asia-Pacific was between Jeddah and Riyadh in Saudi Arabia, coming in at fifth with 9.8 million seats, which represented an increase of 13% year over year.

Hong Kong-Taipei was the busiest cross-border route, with 6.8 million seats, followed by Cairo-Jeddah with 5.8 million seats and Kuala Lumpur-Singapore with 5.6 million seats. The only North American route that made the Top 10 cross-border routes was New York-JFK to London Heathrow, coming in 10th with nearly 4 million seats. 

The route between JFK and Los Angeles was the busiest in 2025 for US domestic flights, at more than 3.4 million seats. Capacity on this route grew 9% year over year, but remains 20% lower than in 2019, according to OAG.

The second-place New York LaGuardia – Chicago O’Hare route had 3.3 million seats, a 7% increase year over year. It also remains below 2019 levels, by 13%.