Cities have a certain pride in their airports, which is most evident when someone believes they’ve lost it. That’s pretty much what happened this winter when the mayor of Chicago declared that O’Hare International was now the busiest airport in the nation, breaking a years-long streak that Atlanta had maintained with little protest. It was presented more as a civic comeback tale than as a transportation statistic.
Chicago’s figures were accurate. According to Federal Aviation Administration data, O’Hare saw 857,392 aircraft take off or land in 2025—a 10.5% increase over 2024—while Atlanta saw 807,625 arrivals and departures. O’Hare wins by that count, and it’s not even close. It is “more than a statistic,” according to Mayor Brandon Johnson, who described it as a statement about the city’s momentum. It’s difficult to ignore how much Chicago wanted this when reading that; there’s something almost nostalgic about a city honoring runway throughput like a championship banner.
Naturally, Atlanta did not see it that way. This is where things start to get interesting because Atlanta has a counterargument that is more than just wounded pride. The leadership of Hartsfield-Jackson focused on passengers rather than flights. Atlanta came in first place with 108.1 million passengers in 2024, while O’Hare came in eighth place with 80 million, according to Airports Council International’s passenger-traffic measure, which is the international standard used to define “busiest.” There is a huge gap there. Atlanta had 89.5 million passengers through October compared to O’Hare’s 66.8 million, according to the Bureau of Transportation Statistics.
Which city is correct, then? The unsettling truth is that both, in a way. Ricky Smith, general manager of Hartsfield-Jackson, put it simply: passenger volume measures what people truly mean when they say an airport is busy—how many people pass through it—while aircraft operations can be inflated by flight frequency and smaller planes. It’s a valid point. Even when a regional jet is only partially full of passengers, it still counts as one operation. It’s also one operation to fill a wide-body to Tokyo. The metrics don’t capture the same reality.
Chicago may have chosen its preferred number despite being aware of this, as is common in cities. The January release of the OAG capacity rankings adds even more complexity by adding a third frame. Atlanta continued to lead in 2025 with 63.1 million scheduled airline seats, but Dubai trailed closely behind with 62.4 million and is rapidly catching up. Dubai’s capacity increased by 4% and is currently 16% higher than it was in 2019. Thus, while Americans quarrel over O’Hare versus Atlanta, there may be a more significant long-term threat to the monarchy coming from somewhere else.
As I watch this develop, I’m struck by how the definition itself has turned into a contest. Nobody really discussed this for decades. Only in 2020, when the pandemic cleared the skies, did Atlanta lose the title of busiest city in the world for 27 of the previous 28 years. The streak was so well-established that it was printed on souvenir mugs as a sort of background fact. The title now seems to have broken up into multiple titles, each of which can be justified and selected by the person who stands to gain from it.
Additionally, there is a forward-looking question that no one has fully addressed. Of the top ten cities in the world, O’Hare and Istanbul had the biggest growth, with O’Hare adding 8% capacity. If that rate continues, the passenger gap will also close, making Atlanta’s case more difficult each year. The Midwest retains its asterisk and the South retains its crown for the time being. In five years, ask again.
