The world's busiest air route isn't from New York to Los Angeles, nor is it from London to Paris. Surprisingly, perhaps, the world's most crowded flight path is the 282 mile connection between the South Korean island of Jeju and the capital Seoul. Last year, there were 64,991 departures between Jeju and Seoul Gimpo, equating to an impressive 178 per day, according to UK-based aviation data monitor OAG.  Interestingly, the route is hugely popular due to tourism rather than business.
Jeju is the largest island off the coast of the Korean Peninsula and it has become a hugely popular holiday destination. Sometimes labeled "the Hawaii of South Korea", it boasts dramatic volcanic landscapes that have been designated a UNESCO World Natural Heritage Site as well as stunning hiking trails and pristine beaches. Even though most of its tourism is domestic, Jeju is starting to lure more international visitors, particularly tourists from China. It has become so popular among Koreans that a domestic flight between Jeju and Seoul departs every 15 minutes on average.
The world's ten busiest air routes are all domestic with the 443 mile stretch from Melbourne to Sydney in second place with 54,519 departures. Mumbai to Delhi rounds off the top three with 47,462 departures last year. The first U.S. route on the list is from Los Angeles to San Francisco but it only comes seventh with just under 35,000 departures last year. The busiest international flight path comes 11th overall and it's the route between Hong Kong and Taipei. Last year, that connection had a total of 29,494 departures. Kuala Lumpur to Singapore was the second busiest international route last year, followed by Jakarta to Singapore.
*Click below to enlarge (charted by Statista)
Statista
Number of departures on the world's busiest air routes in 2017