Montréal–Mirabel International Airport (IATA: YMX, ICAO: CYMX), originally called Montréal International Airport, widely known as Mirabel and branded as YMX International Aerocity of Mirabel, is a cargo and former international passenger airport in Mirabel, Quebec, Canada, 21 nautical miles (39 km; 24 mi) northwest of Montreal. It opened on October 4, 1975, and the last commercial passenger flight took off on October 31, 2004.

The airport's main traffic are cargo flights, but it is also home to MEDEVAC and general aviation flights, and hosts a manufacturing plant for Airbus, where final assembly of the Airbus A220 (formerly Bombardier CSeries) is conducted. Bombardier Aviation produced the Bombardier CRJ700 series of regional jets at the factory until early 2021. The former passenger terminal apron is now a racing course, and the terminal building was demolished in 2016.

Prior to the demolition of the passenger terminal, Montréal–Mirabel International Airport was classified as an airport of entry (AOE) by Nav Canada and was staffed by the Canada Border Services Agency (CBSA). A smaller AOE is still available at the Hélibellule FBO. It is part of the National Airports System. It was one of two airports in Canada with sufficient right-of-way that can be expanded to accommodate 50 million passengers per year, the other being Toronto Pearson International Airport. A lack of traffic meant that Mirabel was never expanded beyond its first phase. As a result of a controversial expropriation, Mirabel was the largest airport in the world by surface area, with a planned area of 39,660 hectares (396.6 km2; 98,000 acres), until surpassed by King Fahd International Airport in 1999.