Chicago O'Hare Airport is forecast to overtake the world’s busiest hub — Hartsfield-Jackson Atlanta International — for the airport with the most scheduled flights.
According to aviation data firm Cirium, Chicago has 437,191 scheduled flights in the first half of 2026, compared with 389,663 for Atlanta.
This shows a 13 percent year-over-year increase for Chicago, with 386,326 flights over the same period in 2025.
These statistics put Chicago on a trajectory for becoming the world’s busiest airport.
Traditionally, this crown goes to the hub with the highest seat capacity. By this metric, Atlanta remains No.1, with 63.1 million seats in 2025 and a forecast of 31,134,246 for the first half of 2026, compared to Chicago’s 26,694,997.
However, Atlanta has historically led on scheduled flights, too, recording around 387,000 last year versus Chicago’s 386,000.
The discrepancy between Chicago’s scheduled flight statistics and seat capacity can be explained by looking at the type of aircraft that frequent the hub.
There is a larger number of smaller regional jets at Chicago, with a higher quantity of mainline aircraft with more seats arriving and departing from Atlanta.
Underpinning growth at O'Hare are American Airlines and United, which have both expanded operations there.
According to Cirium, American is operating around 22.1 percent more flights from Chicago O’Hare in the first half of 2026 compared to the same period in 2025, and United’s flight numbers are up around 12 percent year on year.
The busiest month for Chicago in the first half of 2026 is scheduled to be May 2026, with over 81,000 flights.
