Chicago O-Hare International Airport

Situated around 17 miles northwest of the Loop commercial sector on the Northwest Side of Chicago, Illinois, United States, Chicago O'Hare International Airport is a major international airport servicing the city. As of November 2022, O'Hare, which occupies 7,627 acres and is run by the Chicago Department of Aviation, had nonstop service to 214 locations in North America, South America, the Caribbean, Europe, Africa, Asia, the Middle East, Oceania, and the North Atlantic. O'Hare is predicted to be the most connected airport in the world as of 2023. It is also the seventh-biggest and fourth-busiest airport in the United States.

Built as an alternative to Chicago's Midway International Airport, which was formerly dubbed the "busiest square mile in the world," O'Hare started out as an airport during World War II that served a Douglas production facility for C-54 military transports. In the middle of the 1940s, it was renamed Orchard Field Airport and given the IATA code ORD. It was renamed in 1949 in honor of pilot Edward "Butch" O'Hare, who was the first American Navy Medal of Honor recipient of that conflict. O'Hare was the first large airport to be designed following World War II, and its avant-garde architecture introduced ideas including concourses, jet bridges, direct freeway access to the terminal, and subterranean refueling systems. During the jet era, O'Hare rose to prominence as the busiest airport in the world by passenger volume, a title it held from 1963 until 1998. Based on the rankings published by Airports Council International, it remains one of the busiest airports globally.

The largest airport in the world, O'Hare boasts 213 gates spread throughout four numbered passenger terminals, nine lettered concourses, and a total of 213 gates. A walkway connects Terminals 1-3 on the airside. Since Terminal 5 is divided from the other terminals by a network of taxiways that bridge over the airport's entrance road, most travelers must first go through security, then board a shuttle bus or use the Airport Transit System before going through security again. Terminals 1 and 3 and Terminal 5 may be reached airside via an extra shuttle vehicle. One parallel runway set is located on each side of the terminal complex at O'Hare. Currently the sole hotel on airport grounds, the Hilton Chicago O'Hare is located between the parking garage and the terminal core.