United maintains lead over American in Chicago O’Hare hub rivalry

United recently received approval to use six additional gates at O'Hare as part of its growth strategy. Andrew Nocella, Chief Commercial Officer of United Airlines, commented on this development: "Our current facilities are very full, and we know people want to fly in peak periods so these six gates will allow us to continue to execute on the United Next plan. We've been very consistent in our strategy here in Chicago, and as a result of that, we've got the six gates, and we're going to continue to grow. We think the economics of the hub look really darn good right now."

While no major international expansion is currently planned by United from O'Hare, new domestic routes will soon launch to Dayton and Green Bay. The airline already serves several significant international destinations such as London Heathrow Airport, Paris Charles de Gaulle Airport, Frankfurt Airport, and Tokyo Haneda Airport.

American Airlines' recovery after the COVID-19 pandemic was slower due to aircraft retirements and delivery delays affecting its ability to expand internationally from O'Hare. However, it has recently announced new international routes including Curaçao; Querétaro; Sint Maarten; and St. Croix. Several previously operated routes—such as Honolulu; Mexico City; San José; and Guatemala City—will also resume before the end of 2025.

A dispute over gate allocation has emerged following United's receipt of additional gates at O'Hare. American Airlines filed a lawsuit against the city regarding this decision amid ongoing airport expansion under the O’Hare 21 project. In a statement provided to The Points Guy about their position on gate reallocation at ORD:

"American is committed to keeping O'Hare competitive, as our presence yields more extensive flight schedules for our Chicagoland customers and travelers from across the world, making the city a more desirable destination for business development. That's why we're rejecting the Chicago Department of Aviation's (CDA) improper trigger of the reallocation of gates at O'Hare - it's not only a violation of the agreement signed in 2018 but it stifles the competitive essence of the dual-hub by inhibiting our continued growth."

O’Hare’s expansion project includes two new concourses along with additional gates and lounges at Terminals 2 and 5 which may impact future operations for both airlines.

When examining international traffic from Chicago O’Hare by passenger numbers on specific routes: London Heathrow leads with over one million passengers annually served by American Airlines,British Airways, and United Airlines; Toronto Pearson follows with Air Canada,American, and United; Cancun ranks third served by multiple carriers including both US majors; Mexico City is fourth with service by Aeroméxico,United, Viva Aerobus,Volaris; Frankfurt rounds out fifth place via Lufthansa,United.

Overall figures show that United currently dominates operations at ORD with more than four million seats available monthly compared with just over three million offered by American during August 2025.

The outcome of American’s legal challenge regarding gate allocations remains uncertain as both airlines seek growth opportunities amid ongoing airport developments.