The past year was a busy one for air travel, with high demand for international flights and certain domestic routes within the United States.
A new report released by aviation analytics firm OAG now shows which routes were the busiest in 2025, both in the U.S. and around the world.
The rankings are based on routes with the highest number of seats in 2025, according to OAG’s Global Airline Schedules Data.
The busiest domestic route in the U.S. was the popular transcontinental hop from New York JFK to Los Angeles (LAX), which saw a total of 3.43 million seats for 2025, a year-over-year increase of nine percent.
Rounding out the top three busiest domestic corridors were New York LaGuardia (LGA) to Chicago (ORD), which scored second place with a seven percent increase in seat capacity, and Los Angeles (LAX) to San Francisco (SFO) ranked third busiest, with an annual capacity that grew by five percent.
Top 10 Busiest Domestic Routes in the U.S. for 2025
New York JFK to Los Angeles (LAX) with 3,431,159 seatsNew York LaGuardia (LGA) to Chicago (ORD) with 3,334,011 seatsLos Angeles (LAX) to San Francisco (SFO) with 3,306,223 seatsLas Vegas (LAS) to Los Angeles (LAX) with 3,283,510 seatsAtlanta (ATL) to Orlando (MCO) with 3,226,190 seatsDenver (DEN) to Phoenix (PHX) with 3,118,880 seats Honolulu (HNL) to Kahului (OGG) with 3,045,165 seatsLos Angeles (LAX) to Chicago (ORD) with 2,793,178 seatsAtlanta (ATL) to New York LaGuardia (LGA) with 2,763,776 seatsAtlanta (ATL) to Fort Lauderdale (FLL) with 2,631,730 seats
“The busiest routes highlight a strong US market in 2025, with fierce competition between both legacy and low-cost carriers,” said John Grant, OAG’s chief analyst. “With key airport pairs seeing higher than average rates of growth, there remains an appetite from both airlines and travellers on these key routes and more capacity returned to the market through the year.
However, not all of the U.S.’s busiest domestic routes showed capacity growth in 2025. In fact, two leisure-focused routes, including Atlanta to Orlando and Honolulu to Kahului, saw annual seat capacity soften significantly by -7% and -10%, respectively.
Outside of domestic routes, the busiest international route from the U.S. was New York JFK to London Heathrow (LHR) with nearly 4 million seats in 2025. That route also made it into the top 10 busiest international routes in the world for 2025, OAG’s data shows, and the only route in the global top 10 outside of the Middle East or Asia.
“London Heathrow [to] New York JFK remains the busiest single route with airlines consistently adding new products in the premium cabins as they seek to attract higher yielding customers,” Grant said.
Busiest International Routes Worldwide for 2025
Hong Kong (HKG) to Taipei (TPE) with 6,832,683 seatsCairo (CAI) to Jeddah (JED) with 5,753,491 seatsKuala Lumpur (KUL) to Singapore Changi (SIN) with 5,574,409 seatsSeoul Incheon (ICN) to Tokyo Narita (NRT) with 5,069,779 seatsSeoul Incheon (ICN) to Osaka Kansai (KIX) with 4,959,596 seatsJakarta (CKG) to Singapore Changi (SIN) with 4,619,323 seatsDubai (DXB) to Riyadh (RUD) with 4,465,632 seatsBangkok (BKK) to Hong Kong (HKG) with 4,169,125 seatsTokyo Narita (NRT) to Taipei (TPE) with 4,021,181 seatsNew York JFK to London Heathrow (LHR) with 3,971,000 seats
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