Over 10 million passengers flew on the two-hour route.
The busiest was Jeju-Seoul with 13.7 million passengers, followed by Sapporo New Chitose Apt-Tokyo with 11.9 million and Fukuoka – Tokyo with 11.2 million.
The route from Melbourne to Sydney came in fifth.
The rest of the top 10 were Beijing - Shanghai Hongqiao, Tokyo Haneda - Okinawa Naha, Jeddah – Riyadh, Mumbai - Delhi and Jakarta - Denpasar-Bali.
According to OAG, Kuala Lumpur-Singapore was the world's busiest international route this year with 4.89 million passengers, followed by Cairo-Jeddah and Hong Kong-Taipei.