The definition of world's busiest airport has been specified by the Airports Council International in Montreal, Canada. The ACI defines and measures the following three types of airport traffic: Passenger traffic: total passengers embarked and disembarked, passengers in transit counted once Cargo traffic: loaded and unloaded freight and mail, by mass Traffic movements: landings and take-offs of aircraft Busiest airports The following airports make claims based on objective volume measures that are defined above (as per ACI): Hartsfield–Jackson Atlanta International Airport, Atlanta, Georgia, United States Most passengers annually (1998–2019, 2021–present) Most aircraft movements annually (2015–present) Guangzhou Baiyun International Airport, Guangzhou, Guangdong, China Most passengers annually (2020) Dubai International Airport, Dubai, United Arab Emirates Most international passengers annually (2014–present) Memphis International Airport, Memphis, Tennessee, United States Most cargo traffic by weight annually (2020–2021) Hong Kong International Airport, New Territories, Hong Kong, Hong Kong SAR. Most cargo traffic by weight annually (2022-Present) Busiest city destination Airports of London combined, London, United Kingdom Most passengers annually in all city airports combined (2010–present) Historical claims Midway International Airport, Chicago, Illinois, United States In the late 1940s, Chicago Midway was the busiest airport in the United States by total aircraft operations – i.e., including every training aircraft practicing take-offs and landings. New York LaGuardia had the most airline operations and passengers until the early 1950s, when Chicago Midway became the busiest airport in the United States by any criterion. Before World War II, Chicago Midway was the origin or destination of one in four U.S. airline flights, although a 1939 Official Aviation Guide shows more airline flights scheduled at Newark than at Chicago. Memphis International Airport, Memphis, Tennessee, United States As the home of FedEx Express, Memphis had the largest cargo operations worldwide from 1993 to 2009. It remains the busiest cargo airport in the United States and the Western Hemisphere. See also Lists of airports List of busiest airports by passenger traffic List of busiest airports by international passenger traffic List of busiest airports by cargo traffic List of busiest city airport systems by passenger traffic List of the busiest airports in the European Union List of the busiest airports in the Nordic countries List of the busiest airports in the Baltic states List of the busiest airports in Central America List of busiest airports in the United Kingdom List of the busiest airports in the Republic of Ireland List of the busiest airports