Not So Fast: Has Chicago Overtaken Atlanta As Country’s Busiest Airport?

There are a lot of headlines right now about how Chicago O’Hare (ORD) has become the busiest airport in the United States, overtaking Hartsfield-Jackson Atlanta (ATL). That’s interesting, because Atlanta has for years not only been the busiest airport in the country, but also the busiest airport in the world. So what has really happened here? Are the Windy City’s claims accurate?

“Chicago O’Hare crowned America’s busiest airfield”

Chicago Mayor Brandon Johnson has issued a press release, declaring Chicago O’Hare the busiest airfield in the United States:

• In 2025, the airport saw 857,392 takeoffs and landings, more than any other airport in the country
• As a point of comparison, in 2024, the airport had 776,036 takeoffs and landings, meaning traffic grew around 10% year-over-year, which is impressive

How far ahead of Hartsfield-Jackson Atlanta was Chicago O’Hare?

• In 2025, the airport saw 807,625 takeoffs and landings, meaning Chicago saw around 6% more movements than Atlanta
• As a point of comparison, in 2024, the airport had 796,224 takeoffs and landings, meaning traffic grew only a little over 1% year-over-year, which isn’t so impressive

For what it’s worth, by this metric, the other top five airports in the country were Dallas-Fort Worth (DFW), Denver (DEN), and Las Vegas (LAS).

Here’s how Mayor Johnson describes this achievement for Chicago:

“This is more than a statistic, it’s a statement about Chicago’s momentum. From the runways of O’Hare to the neighborhoods across our city, Chicago is building, growing, and leading. We are open for business, open to the world, and once again setting the pace for the nation.” 

Has Chicago really overtaken Atlanta? Not quite…

The Chicago Mayor is technically correct — Chicago O’Hare has become the busiest airfield, which is to say that it has the most aircraft movements. What’s interesting is how the media at large has picked up on this. Most stories suggest that Chicago now has the busiest airport in the country, but that’s not using the traditional metrics.

If you look at data from OAG, Hartsfield-Jackson Atlanta had 63.1 million departing seats in 2025, compared to Chicago O’Hare’s 50.6 million seats. By that metric, Atlanta has the world’s busiest airport, while Chicago has the world’s eighth busiest airport, and the difference in traffic between the airports is around 25%.

So what gives here? How can there be such a big difference between the number of seats and the number of takeoffs and landings? It’s quite simple — the average aircraft size in Atlanta is way bigger than in Chicago:

• Chicago O’Hare is a massive regional jet market, given that you have both American and United competing, with so many frequencies served by regional jets
• Hartsfield-Jackson Atlanta is a fortress hub for Delta, so the airline largely flies big, mainline aircraft to the airport, rather than smaller regional jets

Private jets can also play a small factor here, but I think it’s not as significant as what’s covered above. There’s no right or wrong way to define a “busy” airport. If you’re worried about whether the taxiway will be congested, then total number of movements is important (and gosh, O’Hare taxiway situation has sucked for a very long time).

Meanwhile if you’re worried about the terminal being crowded, then total number of passengers is important. By Chicago’s metrics of “busy,” Dubai would be considered a rather quiet airport, given that the average plane there is massive (Emirates has an all wide body fleet). That means the airport sees a ton of passengers, but not that many aircraft takeoffs and landings.

Anyway, with American and United competing so fiercely in Chicago, I wouldn’t be surprised to see Chicago narrow the gap on Atlanta a bit in 2026, but I wouldn’t expect passenger numbers in Chicago to exceed those in Atlanta.

Bottom line

Chicago O’Hare claims to now be the busiest airfield in the country. That’s true, which is to say that the airfield sees the most takeoffs and landings. What’s not quite true is how it’s widely being reported that Chicago O’Hare has overtaken Hartsfield-Jackson Atlanta as the world’s busiest airport, if we’re measuring by passenger numbers (which is typically what people care about).

So while Chicago saw 6% more aircraft movements in 2025, Atlanta still saw around 25% more passengers. This comes down to the average aircraft size being much bigger in Atlanta… it’s that simple.

What do you make of this Atlanta vs. Chicago size battle?