The International Air Transport Association’s (IATA) World Air Transport Statistics (WATS) report, released on July 16, 2026, shows that nine of the 10 busiest routes in 2025 were domestic flights in the Asia-Pacific region. South Korea’s Jeju International Airport (CJU) – Seoul’s Gimpo International Airport (GMP) route ranked first, with 13.3 million passengers in 2025.
Japanese routes dominate
This edition of the WATS report shows that the world’s top 10 busiest routes were domestic flights serving a combined 78.2 million passengers throughout the year.
Japan had the most routes in the top 10, with routes from Sapporo (CTS) and Fukuoka (FUK) to Tokyo Haneda (HND), and from HND to Okinawa (OKA), ranking second, third, and seventh, respectively, and totalling 24.8 million passengers.
Saudi Arabia’s King Abdulaziz International Airport (JED) in Jeddah and King Khalid International Airport (RUH) in Riyadh were the only pair in the top 10 busiest routes outside the Asia-Pacific region, ranking fifth with 7 million passengers.
Other key insights
The IATA report also showed that premium-class travel in Latin America and the Caribbean jumped the highest across all regions in 2025, serving an extra 4 million passengers and growing 22.1%. The report also showed that Airbus A319 flights decreased by 34.3% from 2019 to 2025, dropping from 2.1 million to 1.4 million.
Airbus plans to retire the A319 by 2029, according to FlightGlobal, with airlines such as EasyJet announcing they will also stop using the aircraft that year.
Japan accounted for the world’s fastest-growing passenger market in 2025, growing by 9.2% to 223.5 million total passengers and ranking as the fifth largest passenger market. Other significantly growing passenger markets included Italy at a 5.8% growth margin (187.3 million passengers), Spain at 5% (252.7 million passengers), and the People’s Republic of China (PRC) at 4.8% (776.1 million passengers).
The U.S. was the largest market (890.1 million passengers), with China the second-largest (776.1 million passengers) and the United Kingdom the third-largest (269.7 million passengers).
Which of the WATS insights fascinated you the most? Tell us in the comments below!
