In 2008, the airport had 881,566 aircraft operations, an average of 2,409 per day (64% scheduled commercial, 33% air taxi, 3% general aviation and <1% military).^[1] O'Hare International Airport is the second busiest airport in the world behind Atlanta Hartsfield Airport, with 69,353,654 passengers passing through the airport in 2008, a -8.96% change from 2007.^[3] O'Hare also has a strong international presence, with flights to more than 60 foreign destinations. O'Hare is the fourth busiest international gateway in the United States with only John F. Kennedy International Airport in New York City, Los Angeles International Airport and Miami International Airport serving more international passengers.

O’Hare International Airport has been voted the "Best Airport in North America" for 10 years, by readers of the U.S. Edition of Business Traveler Magazine (1998–2003) and Global Traveler Magazine (2004–2007).^[4]

Most of O'Hare Airport is in Cook County, but a section of the southwest part of the airport is in DuPage County.

Although O'Hare is Chicago's primary airport, Chicago Midway International Airport, the city's second airport, is about 10 miles (16 km) closer to the Loop, the main business and financial district.