Chicago O'Hare International Airport (IATA: ORD, ICAO: KORD, FAA LID: ORD), also known as O'Hare Airport, Chicago International Airport, Chicago O'Hare or simply O'Hare, is an international airport located on the Far Northwest Side of Chicago, Illinois, 17 miles (27 km) northwest of the Loop. It is the primary airport serving the Chicago metropolitan area, with Midway International Airport, about 10 miles (16 km) closer to the Loop, serving as a secondary airport. It is operated by the City of Chicago Department of Aviation.
O'Hare was the busiest airport in the world by number of takeoffs and landings in 2014, beating out Hartsfield-Jackson Atlanta International Airport (which had the title from 2005 to 2013); however, it lost the title back to Atlanta a year later. Until 1998, O'Hare was also the busiest airport in the world in number of passengers. It was surpassed mainly due to limits imposed on the airport by the federal government to reduce flight delays. As of 2015, O'Hare is the fourth-busiest airport in the world by passenger traffic. O'Hare also has the most runways (9) of any major international airport.
As of September 2014, O'Hare has direct service to a total of 210 destinations, including 153 domestic destinations in the United States and 57 international destinations in North America, South America, Asia and Europe. O'Hare is among a select group of airports worldwide with the distinction of serving more than 200 destinations, along with Heathrow, Frankfurt, Istanbul, Amsterdam, Charles de Gaulle, Atlanta, Dallas/Fort Worth, Munich, and Dubai.
O'Hare is currently a major hub for American Airlines and United Airlines, as well as a hub for regional carrier Air Choice One and a focus city for Frontier Airlines and Spirit Airlines. It is the second-largest passenger-carrying hub for United after Houston's George Bush Intercontinental Airport carrying 15.3 million passengers annually, and largest by number of daily flights, operating a total of 585 flights daily. O'Hare is American's third-largest hub, behind Dallas/Fort Worth International Airport and Charlotte Douglas International Airport, and third-largest by number of daily flights, operating a total of 527 daily flights to 120 destinations, including 201 mainline flights daily.
O'Hare was voted the "Best Airport in North America" for 10 years by two separate sources: Readers of the U.S. Edition of Business Traveler Magazine (1998–2003) and Global Traveler Magazine (2004–2007). Contrastingly, Travel and Leisure magazine's 2009 "America's Favorite Cities" ranked Chicago's Airport System (O'Hare and Midway) the second-worst for delays, New York City's airport system (JFK, Newark Liberty, and LaGuardia) being the first. O'Hare currently accounts for nearly 20% of the nation's total flight cancellations and delays.