These Are the Busiest Flight Routes in the World

As more travelers took to the skies this year, these flight paths in the United States and globally saw the greatest numbers of passengers.

Illustration of a globe depicting four international flight routes

Did you fly on any of the busiest international or domestic flight routes in 2023?

Illustration by Shutterstock

This fall, international air traffic reached 98.2 percent of what it was prepandemic, according to the latest data from the International Air Transport Association (IATA). In other words, global citizens are traveling the world with almost the same fervor as they were in 2019.

“Every day sees the recovery develop, and by the end of 2024 we should be back to 2019 levels,” John Grant, chief analyst at global travel industry data provider OAG, tells AFAR.

That return in international travel means that the skies have become busy again. So, where is everyone going? On December 20, OAG unveiled the flight routes that saw the highest number of passengers this year (tabulated based on the number of passenger seats flown). The 2023 list “includes many of the tried and tested airport pairs that dominated the list prepandemic,” says Grant. But there are also some notable changes.

The world’s busiest international airline route in 2023 is Kuala Lumpur, Malaysia, to Singapore Changi with 4.9 million seats, a route that ranked second four years ago.

Beyond just general curiosity and providing travelers with a better sense of global flight patterns, knowing which routes are most popular can help travelers in other ways, too. For instance, when you look for affordable airfares, typically flight paths with more service are also more competitive—meaning that you are likely to find better rates on those routes. So, you can also try to strategize your search around higher-volume routes to see if you can find a lower price to get to your final destination. For instance, if you want to fly to Europe, you could try combining a flight between JFK and Heathrow, which is on the list of top 10 busiest routes, with shorter hops on either side of the pond.

The world’s busiest airline routes in 2023

Illustrated chart of world's 10 busiest flight paths in 2023

Many of the world’s busiest flight routes in 2023 are in Asia.

Courtesy of Lewis Harper/OAG

  1. Kuala Lumpur, Malaysia (KUL) to Singapore Changi (SIN): 4.9 million seats
  2. Cairo, Egypt (CAI) to Jeddah, Saudi Arabia (JED): 4.8 million seats
  3. Hong Kong (HKG) to Taipei, Taiwan (TPE): 4.6 million seats
  4. Seoul Incheon, Korea (ICN) to Osaka Kansai, Japan (KIX): 4.2 million seats
  5. Seoul Incheon (ICN) to Tokyo Narita, Japan (NRT): 4.15 million seats
  6. Dubai, United Arab Emirates (DBX) to Riyadh, Saudi Arabia (RUH): 3.99 million seats
  7. Jakarta, Indonesia (CGK) to Singapore Changi (SIN): 3.9 million seats
  8. New York City (JFK) to London Heathrow (LHR): 3.88 million seats
  9. Bangkok, Thailand (BKK) to Singapore Changi (SIN): 3.5 million seats
  10. Bangkok (BKK) to Seoul Incheon (ICN): 3.4 million seats

In 2019, the Hong Kong to Taipei route topped the list, followed by Kuala Lumpur to Singapore, and then Jakarta to Singapore in third place. Half of the routes in the above top 10 list were not in the top 10 in 2019, including the Cairo to Jeddah route, Seoul to Osaka, Seoul to Tokyo, Dubai to Riyadh, and Bangkok to Seoul.

And there are likely to be additional shifts in 2024, notes Grant. “In 2024, we should see the re-emergence of the Chinese international traveler, which will be very welcome in key tourism markets in Southeast Asia and that will of course drive more traffic,” says Grant.

He adds that in North America, “the hope remains for traffic to Northeast Asia to rebuild with destinations such as China, Japan, and South Korea likely to benefit.”

As for domestic travel, OAG also looked at which flight routes were dominant within the United States. Here’s what it found.

The busiest flight routes in the United States in 2023

When it comes to U.S. domestic travel, flights between popular Hawaiian islands and between major hubs like Atlanta, Orlando, New York City , Los Angeles, San Francisco, Denver, and Las Vegas dominated the list. Here’s which U.S. routes saw the highest number of passenger seats in 2023.

  1. Honolulu, Hawai‘i (HNL) to Kahului, Maui (OGG): 3.6 million seats
  2. Atlanta (ATL) to Orlando (MCO): 3.52 million seats
  3. Las Vegas (LAS) to Los Angeles (LAX): 3.49 million seats
  4. New York City (JFK) to Los Angeles (LAX): 3.24 million seats
  5. Denver (DEN) to Las Vegas (LAS): 3.19 million seats
  6. Los Angeles (LAX) to San Francisco (SFO): 3.13 million seats
  7. Atlanta (ATL) to Fort Lauderdale (FLL): 3.05 million seats
  8. Denver (DEN) to Phoenix (PHX): 3.04 million seats
  9. Atlanta (ATL) to New York LaGuardia (LGA): 2.7 million seats
  10. Los Angeles (LAX) to Chicago O’Hare (ORD): 2.67 million seats

Interestingly, Honolulu to Kahului, which topped the list this year, was not among the top 10 busiest domestic routes in 2019 and ranked third in 2022. Denver to Las Vegas and Denver to Phoenix were also absent from the 2019 list, when Los Angeles to San Francisco ranked as the busiest route in the United States.

Michelle Baran is a deputy editor at AFAR where she oversees breaking news, travel intel, airline, cruise, and consumer travel news. Baran joined AFAR in August 2018 after an 11-year run as a senior editor and reporter at leading travel industry newspaper Travel Weekly.
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