These Are The Top Non-US Airlines At The World's Busiest Airport

For many years, Hartsfield-Jackson Atlanta International Airport (ATL) in the US federal state of Georgia has widely been known as the busiest airport in the entire world by passenger numbers. A key reason behind the huge scale of its operations is the presence of the US ‘big three’ legacy carrier and SkyTeam founding member Delta Air Lines, which calls Atlanta its home. However, what does the picture look like for non-US airlines?

According to present scheduling data made available by Cirium, an aviation analytics company, carriers from outside of the United States of America are set to operate a grand total of 1,478 flights to and from Atlanta this month. While Mexican and Canadian airlines dominate, there is also coverage from further afield.

Aeromexico Sits At The Top Of The Pile

Data from Cirium shows that Aeromexico is Atlanta’s top non-US carrier in December 2025, with 232 flights and 22,968 seats scheduled to and from the Georgia hub this month. As pictured above, all of these services are operated by the Mexican flag carrier’s Aeromexico Connect regional brand using Brazilian-built Embraer E190 twinjets. According to aeroLOPA, these aircraft have 11 business class and 88 economy class seats.

All in all, Aeromexico serves four destinations from Atlanta, with three of these routes seeing a round-trip flight operating every day this month. The corridors in question link Atlanta with Bajio (BJX), Queretaro (QRO), and San Luis Potosi (SLP), while Monterrey (MTY) will only be served daily until December 23. The San Luis Potosi to Atlanta route only launched in June of this year, with Aeromexico explaining at the time of the launch that:

“Thanks to the Joint Collaboration Agreement with Delta, these new routes will bring the total number of destinations connecting Mexico and the US to 26, through 57 routes and a joint operation of more than 90 daily flights.”

Canada Is A Key Market

Just like Mexico to the south, Canada is also an important market when it comes to international travel to and from Atlanta. The top non-US operator on this front is WestJet, with the carrier having penciled in 184 flights and 27,510 seats on its various routes to and from Hartsfield-Jackson Airport this month. It favors the Boeing 737 family for these operations, with the 737-700, 737-800, and 737 MAX 8 among the variants used on these routes.

Calgary (YYC) is comfortably the top destination by frequency, with more than a flight a day in each direction on average. WestJet’s coverage of this transborder corridor amounts to 11 flights each way every week this month, putting it a long way ahead of its second-busiest Atlanta-bound route from Edmonton (YEG), which has four weekly rotations. Meanwhile, Vancouver (YVR) and Winnipeg (YWG) are served on a thrice-weekly basis.

The other Canadian operator serving Atlanta this month is flag carrier Air Canada, with 178 flights and 13,528 seats. These services are all flown by Embraer E175 regional jets under the Air Canada Express banner by its partner Jazz, with Toronto (YYZ) served twice a day for almost the entire month. Meanwhile, Montreal (YUL) has daily flights, and it is interesting to note that there are no routes served by both WestJet and Air Canada.

Europe & Beyond

Further afield, Atlanta also has a growing transatlantic market, with its top European operator being Delta’s SkyTeam partner KLM. The Dutch flag carrier has 124 flights to and from the Georgia hub this month using Boeing 777 and 787 twinjets, representing two round trips a day from its base in Amsterdam (AMS).

Not far behind are fellow SkyTeam members Air France and Virgin Atlantic, with a combined 116 and 108 flights respectively between Atlanta and their hubs at Paris CDG Airport and London Heathrow (LHR). Turkish Airlines also averages more than a round trip a day, with 40 round trips from Istanbul (IST), while British Airways, Etihad, Kenya Airways, LATAM, and Qatar Airways can all be seen on a daily basis in Atlanta in December 2025.