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 main role of the airport today is cargo flights, but it is also home to MEDEVAC and general aviation flights, and is a manufacturing base for Airbus Canada, where final assembly of the Airbus A220 (formerly Bombardier CSeries) is conducted. Bombardier Aviation produced the Bombardier CRJ700 series (CRJ700, CRJ900 and CRJ1000) regional jetliners until early 2021 when the last CRJ was produced. The CRJ business was sold to Mitsubishi Heavy Industries but is no longer manufactured. 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 one of only two non-capital airports with fewer than 200,000 passengers a year to be 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.