What Are The World’s Busiest Airline Routes? #1 Has 100+ Daily Flights

Have you ever wondered what the world’s busiest airline routes are? OAG recently published this data for 2025, and I always find these lists to be quite interesting. Some people know exactly which route will be number one on the list, while others are shocked…

What are the world’s busiest air routes by seats?

Let’s use OAG data and look at the world’s busiest airline routes for 2025, based on the number of available seats published in each market. Let’s first look at the busiest routes overall (all of which happen to be domestic), the busiest international routes, and then the busiest domestic US routes. Some may surprise you, while others may not.

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The busiest airline routes in the world

Here are the 10 busiest airline routes in the world, including the number of seats available annually:

1. Jeju (CJU) – Seoul Gimpo (GMP) – 14,384,766 seats
2. Sapporo New Chitose (CTS) – Tokyo Haneda (HND) – 12,099,499 seats
3. Fukuoka (FUK) – Tokyo Haneda (HND) – 11,496,706 seats
4. Hanoi (HAN) – Ho Chi Minh City (SGN) – 11,078,775 seats
5. Jeddah (JED) – Riyadh (RUH) – 9,819,558 seats
6. Melbourne (MEL) – Sydney (SYD) – 8,951,497 seats
7. Tokyo Haneda (HND) – Okinawa Naha (OKA) – 8,052,864 seats
8. Mumbai (BOM) – Delhi (DEL) – 7,642,016 seats
9. Beijing Capital (PEK) – Shanghai Hongqiao (SHA) – 7,454,950 seats
10. Shanghai Hongqiao (SHA) – Shenzhen (SZX) – 7,138,673 seats

The busiest international airline routes in the world

Here are the 10 busiest international airline routes, including the number of seats available annually:

1. Hong Kong (HKG) – Taipei (TPE) – 6,832,683 seats
2. Cairo (CAI) – Jeddah (JED) – 5,753,491 seats
3. Kuala Lumpur (KUL) – Singapore Changi (SIN) – 5,574,409 seats
4. Seoul Incheon (ICN) – Tokyo Narita (NRT) – 5,069,779 seats
5. Seoul Incheon (ICN) – Osaka Kansai (KIX) – 4,959,596 seats
6. Jakarta (CGK) – Singapore (SIN) – 4,619,323 seats
7. Dubai (DXB) – Riyadh (RUH) – 4,465,632 seats
8. Bangkok (BKK) – Hong Kong (HKG) – 4,169,125 seats
9. Tokyo Narita (NRT) – Taipei (TPE) – 4,021,181 seats
10. New York (JFK) – London (LHR) – 3,971,000 seats

The busiest domestic US airline routes

Here are the 10 busiest domestic US airline routes, including the number of seats available:

1. New York JFK (JFK) – Los Angeles (LAX) – 3,431,159 seats
2. New York LaGuardia (LGA) – Chicago O’Hare (ORD) – 3,334,011 seats
3. Los Angeles (LAX) – San Francisco (SFO) – 3,306,223 seats
4. Las Vegas (LAS) – Los Angeles (LAX) – 3,283,510 seats
5. Atlanta (ATL) – Orlando (MCO) – 3,226,190 seats
6. Denver (DEN) – Phoenix (PHX) – 3,118,880 seats
7. Honolulu (HNL) – Kahului (OGG) – 3,045,165 seats
8. Los Angeles (LAX) – Chicago O’Hare (ORD) – 2,793,178 seats
9. Atlanta (ATL) – New York LaGuardia (LGA) – 2,763,776 seats
10. Atlanta (ATL) – Fort Lauderdale (FLL) – 2,631,730 seats

My take on the world’s busiest airline routes

I think people are sometimes surprised by the world’s busiest airline route. Typically that’s for people who simply aren’t familiar with Jeju, but the explanation is quite simple, and the below video does a good job of covering the basics. The idea is that South Korea has a big population, Jeju is the most popular year-round vacation destination, and it can only be reached by air from most parts of the country.

What’s kind of wild is that demand in the market is still down around 20% compared to pre-pandemic, so the current number of passengers isn’t even a record. The market has over 100 flights per day, and it’s basically flight after flight. Just look at the departures board for Jeju currently, where you have 12 flights to Seoul Gimpo over the course of 30 minutes.

What’s my take on the busiest routes beyond that?

• It’s interesting how no international routes rank in the top 10 for traffic globally, with the world’s busiest international route having less than half of the traffic of the Jeju to Seoul Gimpo route
• New York to London is what people might think of as being a particular busy international route, though it’s also amazing how many routes we might overlook or not even think about, like Cairo to Riyadh
• It’s once again fascinating to see the traffic drop-off when looking at the busiest domestic route in the United States, as the highest traffic route has less than one quarter of the seats of the Jeju to Seoul Gimpo route

Bottom line

People are sometimes surprised to learn what the world’s busiest airline routes are, since they’re not necessarily what the average traveler might expect. For years, the market between Jeju and Seoul Gimpo has ranked number one by a long shot.

It’s noteworthy (but perhaps not surprising) how the 10 busiest routes are all domestic. It’s also interesting how no route within the United States ranks anywhere close to being among the busiest in the world.

Do any of the busiest airline routes surprise you?