O’Hare International Airport airport, Chicago, Illinois, United States Also known as: Chicago O’Hare, ORD, Orchard Field Airport Written by Michele Metych Michele Metych is the lead editor for Today in History at Encyclopædia Britannica. Michele Metych Fact-checked by Britannica Editors Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree.... Britannica Editors Last updated June 10, 2026 •History O’Hare International Airport, one of the busiest and most connected airports in the world and the busiest in the Chicago area. Located 17 miles (27 km) northwest of downtown Chicago, O’Hare is a gateway for both domestic and international travel. Serving more than 260 destinations on more than 40 airlines, O’Hare handled 80 million passengers in 2025 and ranked as the world’s busiest airfield that year. Initially known as Douglas Airport, the site was developed...

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