Chicago O'Hare International Airport (IATA: ORD, ICAO: KORD, FAA LID: ORD), also known as O'Hare Airport, O'Hare Field, Chicago Airport, Chicago International Airport, or simply O'Hare, is a major airport located in the northwestern-most corner of Chicago, Illinois, United States, 17 miles (27 km) northwest of the Chicago Loop. It is the primary airport serving the Chicago area, with Chicago Midway International Airport, about 10 miles (16 km) closer to the Loop, serving as a secondary airport for intracontinental flights.
United Airlines is the largest airline at O'Hare, carrying over 45% of passengers. O'Hare is the second-largest hub for United Airlines after Houston-Bush. American Airlines has the second largest operation at O'Hare, carrying 37.08% of passengers. O'Hare is its second-largest hub after Dallas/Fort Worth. The airport used to be a focus city for Mexicana de Aviación and Pan American World Airways before they both ceased operations.