The history of Belfast Airport (originally named Aldergrove) goes all the way back to 1917 when the need for a strategically situated airport to aid in the World War I fighting effort was acute. Many years later, in 1951, Aldergove was involved in history making once again when the first double crossing of the Atlantic in one day by 'Rolly' Beaumont was made here. Continued use of Aldegrove gradually called for further facilities, and in 1963 a new terminal and apron with greater passenger capacity were opened to the public. In 1971 Northern Ireland Airports Limited was part of an effort to improve the airport as a whole. The resulting changes included an extended runway and a new taxiway. A wave of investments followed in the lates 70's and 80's. In July of 1994, Belfast International Airport was privatized. The new owners, part of a management-employee buyout team, purchased the airport for 50 million Pounds, and gave it its current name, Belfast International Airport, Ltd.

A growth of interest in Northern Ireland over the past few years has served to draw large numbers of tourists into the country, necessitating a general expansion of Belfast Airport's already busy schedule. Recently it succeeded in achieving international passenger traffic records, and this positive growth trend is expected to continue in the future. New services to cities such as Manchester, Boston and New York were introduced. A new London Gatwick service became available in 1996.In April 2018, Vinci Airports bought the airport.

In 2018 the airport serviced 6,269,025 passengers and processed 27,672 tons of freight.