Travel data company OAG has once again named London Heathrow the world’s most connected airport.
OAG’s 2025 “Megahub” list, which rates airports based on scheduled connections to and from international flights and number of destinations served, put the U.K.’s busiest airport at No. 1, a position it also held in 2024 and 2023.
London Heathrow offers 59,000 possible connections to 226 destinations on its busiest days. It is Europe’s busiest airport by seat capacity.
“Heathrow’s sustained dominance reflects its vital role in global travel, while Istanbul’s rapid rise shows how hubs are evolving to meet demand,” said John Grant, OAG’s chief analyst, in a news release. “Our 2025 ranking underscores the balance between established gateways and ambitious challengers worldwide, which has developed over ten years of Megahubs.”
London Heathrow led Istanbul Airport and Amsterdam Schiphol, which took spots two and three on OAG’s list, and Kuala Lumpur International Airport and Frankfurt Airport, which tied for fourth place. Seoul Incheon, Chicago O’Hare, Hartsfield-Jackson Atlanta International Airport, Tokyo Haneda, and Paris Charles de Gaulle Airport rounded out the top 10.
The 2024 Megahub list featured a similar top 10 with many of the same airports, though in different positions. Between 2024 and 2025, Istanbul rose from No. 8 to No. 2, Frankfurt moved from No. 10 to No. 4, and Tokyo Haneda fell from No. 3 to No. 9.
Atlanta was ranked No. 11 last year.
Consistent with its place on the international list, Chicago O’Hare was the most connected airport in the U.S., followed by Atlanta, Dallas/Fort Worth, Denver, Charlotte Douglas International Airport in North Carolina, Seattle, Boston, Detroit Metropolitan Wayne County Airport, George Bush Intercontinental Airport in Houston, and Los Angeles International Airport.
Chicago O’Hare and Atlanta tied at No. 1 on the U.S. Megahubs list last year.
