In the world of aviation and travel journalism, OAG (Official Airline Guide) is the gold standard for flight data and analytics. The guide has evolved from a printed directory of flight schedules into a global digital platform that powers the entire travel ecosystem, and releases data sets that are widely recognised across the industry.
The global aviation landscape in 2025 was a tale of two halves: the unwavering dominance of the Asia-Pacific region and the explosive growth of the Middle Eastern corridor. According to the latest data set collated and released by OAG, the world's leading provider of digital flight information, airline capacity has not only recovered in key markets but is surpassing pre-pandemic benchmarks in several high-traffic sectors.
While high-speed rail and digital connectivity continue to evolve, the demand for air travel remains insatiable, particularly for domestic "trunk" routes and regional cross-border hubs. From the short-haul shuttle between Seoul and Jeju to the booming Riyadh-Jeddah connection, these routes represent the vital arteries of global commerce and tourism.
These were the busiest flight routes in 2025
According to data sets released by Official Airline Guide (OAG), these are the busiest flight routes in the world for 2025.
1. Hong Kong (HKG) - Taipei (TPE): This route remains the world’s most traversed international flight path, securing the top cross-border spot in 2025 as it did in both 2024 and pre-pandemic in 2019. While the route offered a substantial 6.8 million seats this year — this is just a 1% increase over 2024 — overall capacity is still trailing its 2019 peak by 14%.
2. Cairo (CAI) - Jeddah (JED): This particular route has emerged as a powerhouse of regional connectivity, recording a staggering 5.8 million seats in 2025. This represents a 5% increase from 2024 and a remarkable 71% surge above 2019 levels. This route has been cemented as being the world’s second busiest international flight route. This surge has been primarily fuelled by low cost carriers servicing the route, which now command 43% of the total capacity on this route.
3. Kuala Lumpur (KUL) - Singapore Changi (SIN): Returning to pre-pandemic strength, this route recorded 5.6 million seats in 2025. This is 4% growth year-on-year, successfully restoring capacity to 2019 levels, solidifying its place as the third busiest international route globally. Despite the high volume, the route remains incredibly affordable; served by seven different carriers.
4. Seoul Incheon (ICN) to Tokyo Narita (NRT): Coming in in fourth place, this route recorded 5.1 million seats in 2025. Surprisingly, this figure was down 6% year-on-year but significantly above the 2019 figures, in fact 58% above.
5: Seoul Incheon (ICN) to Osaka Kansai (KIX): Remaining stable year on year, this route follows closely in fifth position with 5.0 million seats. Versus pre-pandemic data in 2019, this route has seen a 44% increase in popularity.
6. Jakarta (CGK) to Singapore (SIN): This route saw a 14% increase year on year in popularity, with 4.6 million seats recorded. Although these figures are impressive, it still remains 16% below the 2019 reported data. This is the fastest growing route on this list.
7. Dubai (DXB) to Riyadh (RUH): The popularity of this route illustrates the immense demand for Middle East connectivity, recording 4.5 million seats in 2025. This represents a steady 4% increase over the previous year and a remarkable 42% surge above 2019 levels, highlighting the corridor's vital role in the region's expanding aviation landscape.
8. Bangkok (BKK) - Hong Kong (HKG): Slipping from seventh place to eighth, this flight route has experienced approximately 1% decrease in seats, however interest in this route remains strong with more than 4.16 million seats recorded.
9. Tokyo Narita (NRT) - Taipei (TPE): Experiencing 22% growth since pre-pandemic figures in 2019, just over 4 million seats were recorded on this route in 2025.
10. New York (JFK) - London Heathrow (LHW): With 4 million seats recorded in 2025, this trans-Atlantic route experienced a slight drop in capacity (-1%) but has maintained its place in 10th position on this list.
