Summary Chicago O'Hare Airport ranks as the 3rd busiest in the US with 94 million available seats on flights in 2024. United Airlines dominates the market at O'Hare with over 44 million seats and hub-to-hub routes like SFO and Denver. Other major airlines like American, Spirit, Delta, and Southwest also have significant presence and routes at O'Hare.
Chicago O'Hare International Airport is one of the most important airports in the United States. The airport was opened in 1944 and has eight runways that are utilized in different conditions. The airport is famous for its approach over Lake Michigan, flying over the city's skyline and providing incredible views before landing.
According to OAG, ORD is the seventh-busiest airport in the world this month, by number of seats available. With 4,393,280 seats, ORD is the third-busiest airport in the US. Home to United Airlines and also a hub for American Airlines, the airport connected almost 74 million passengers last year.
Data from Cirium , an aviation analytics firm, shows there are more than 94 million available seats on flights to and from O'Hare in 2024. Fifty airlines have scheduled flights at ORD, and United Airlines has the most seats available. United is headquartered in Chicago, making O'Hare its busiest airport.
Nearly half of the available seats at O'Hare in 2024 are offered by United. The top ten airlines are in the table below: Airline Number of seats United Airlines 44,088,236 American Airlines 28,496,346 Spirit Airlines 3,671,704 Delta Air Lines 3,507,581 Southwest Airlines 2,219,909 Frontier Airlines 1,458,938 Alaska Airlines 1,103,186 Air Canada 703,188 Lufthansa 702,561 Volaris 671,009 1 United Airlines 44,088,236 seats United's busiest route by number of seats is from ORD to San Francisco International Airport, one of two California hubs and the most important gateway to Asia. This year, United has 6,888 roundtrip flights scheduled between the two cities.
The airline deploys several aircraft types on the route, including the brand-new Airbus A321neos, which were added to the fleet late last year. Operations on this route are not limited to narrowbodies, as United uses aircraft like the Boeing 777-200s, with dense-domestic configurations. While not a narrowbody, the Boeing 757 is frequently used to connect the two cities as well.
Not far behind ORD is another hub-to-hub route to the Mile High City, Denver. This year, United has 7,205 roundtrip flights scheduled to Denver International Airport. In total, United has 1,563,273 seats available on the route.
Third is to Newark Liberty International Airport, United's most important gateway across the Atlantic Ocean. Throughout 2024, United has 1,458,616 seats available between Newark and Chicago. Below is the list of the top five routes by seat number: Origin Destination Seats Number of flights Chicago San Francisco 1,578,358 6,888 Chicago Denver 1,563,273 7,205 Chicago Newark 1,458,616 8,370 Chicago Los Angeles 1,390,319 6,841 Chicago New York (LaGuardia) 1,391,354 9,771 2 American Airlines 28,496,346 seats American Airlines' busiest route by number of seats is to its home at Dallas Fort Worth International Airport (DFW).
The airline operates several flights daily and has 1,468,799 seats available on the route in 2024. Unlike United, whose busiest route by number of flights and seats differ, this is American's busiest route by both metrics. The Fort-Worth based airline, which has a hub at O'Hare, has 8,081 roundtrip flights on the ORD-DFW route this year.
The second-busiest route is also to an American Airlines hub, Charlotte Douglas International Airport. There are 1,125,348 seats available on this city pair this year, and 6,203 roundtrip flights. At number three is a route to the Southwest US, where American has a hub at Phoenix Sky Harbor International Airport (PHX).
According to Cirium, the airline has 1,079,582 seats from PHX to ORD, and 5,997 flights. Origin Destination Seats Number of flights Chicago Dallas Fort Worth 1,468,799 8,081 Chicago Charlotte 1,125,348 6,203 Chicago Phoenix 1,079,582 5,997 Chicago Los Angeles 1,021,067 5,765 Chicago Miami 992,474 5,768 3 Spirit Airlines 3,671,704 seats The drop from United and American is significant, but Spirit Airlines does have a solid presence at O'Hare. This year, the ultra-low-cost carrier (ULCC) has more than 3.
5 million seats available. Its busiest route is to Fort Lauderdale-Hollywood International Airport (FLL), considered Miami's secondary airport, with 498,602 seats available on 2,753 flights. Number two is a slightly longer flight to Harry Reid International Airport (LAS) in Las Vegas.
It is a crucial city to Spirit's operations, and there are 372,288 seats available on 1,795 flights between ORD and LAS. Rounding out the top three is the route to LaGuardia Airport in New York. Spirit has 1,380 roundtrip flights scheduled and 305,072 seats.
Origin Destination Seats Number of flights Chicago Fort Lauderdale 498,602 2,753 Chicago Charlotte 372,288 1,795 Chicago Phoenix 305,072 1,380 Chicago Los Angeles 274,434 1,370 Chicago Orlando 255,087 1,419 4 Delta Air Lines 3,507,581 seats Delta Air Lines, headquartered in Atlanta, operates out of the world's busiest airport, Hartsfield-Jackson Atlanta International Airport. Its busiest route from Chicago is to Atlanta, with 928,014 seats available in 2024 on 4,888 flights. Its second-busiest route is also in the top five for Spirit and United, to LaGuardia.
This year, Delta has 5,313 flights from ORD to LGA, with a seat offering of 594,382. The last route in the top three is to Delta's hub at Minneapolis Saint Paul International Airport (MSP). Data shows there are 449,098 seats available on 3,904 flights.
Origin Destination Seats Number of flights Chicago Atlanta 928,014 4,888 Chicago LaGuardia 594,382 5,313 Chicago Minneapolis 449,098 3,904 Chicago Detroit 410,732 3,782 Chicago Boston 316,730 2,834 5 Southwest Airlines 2,219,909 seats Southwest Airlines operates at two Chicago airports, O'Hare and Midway Airport. Most of the airline's operations in Chicago are concentrated at Midway, but it still has more than two million available seats at ORD this year. Its busiest route is to Denver, competing with United, which offers more than three times as many seats on the route.
In 2024, Southwest has 493,693 seats between Chicago O'Hare and Denver. Origin Destination Seats Number of flights Chicago Denver 493,693 3,059 Chicago Dallas Love Field 377,677 2,339 Chicago Baltimore 266,453 1,659 Chicago Nashville 256,794 1,638 Chicago Phoenix 228,220 1,412.
