Air Canada, the country's flag carrier, also has its corporate headquarters complex on the Saint-Laurent side of the airport.

The airport is one of two managed and operated by Aéroports de Montréal (ADM), a not-for-profit corporation without share capital; the other is Montréal–Mirabel northwest of Montreal, which was initially intended to replace the one in Dorval but now deals almost solely with cargo and private flights.

[12][13] It is one of three Air Canada hubs and, in that capacity, serves mainly Quebec, the Atlantic Provinces and Eastern Ontario.

Airlines servicing Trudeau offer year-round non-stop flights to five continents, namely Africa, Asia, Europe, North and South America.

The Minister of Transport purchased land at the Dorval Race Track, which was considered the best location for an enlarged airport because of its good weather conditions and few foggy days.

At one time Dorval was the major transatlantic hub for commercial aviation and the busiest airport in Canada, with flights from airlines such as British Overseas Airways Corporation (BOAC).

As the first phase in the transition that would eventually have seen Dorval closed, all international flights (except those to and from the United States) were to be transferred to the new airport in 1975.

[citation needed] The Trudeau government had developed Mirabel Airport to handle an expected growth in international traffic and eventually, to replace Dorval.

Many connecting flights to Canadian centres were transferred to Mirabel and 23 international airlines moved their overseas activities there.

Mirabel's traffic decreased due to the advent in the 1980s of longer-range jets that did not need to refuel in Montreal before crossing the Atlantic Ocean from the major Western North American cities.

Montreal's economic decline in the late 1970s and 1980s also had a significant effect on both airports' traffic, which made Mirabel's additional capacity redundant.

Nonetheless, this was insufficient to woo back international airlines who had already switched their eastern Canadian gateway to Toronto Pearson a decade ago.

The renaming also provoked opposition from many aviation historians and enthusiasts who recalled Trudeau's role in the effort to shutter Dorval in favour of the much larger and modern Mirabel Airport, of which he was the greatest instigator of its construction.

In partnership with the Canada Aviation and Space Museum, the airport hosted the Travelling Through Time exhibition in the public hall of the US Departures area.

Montréal–Trudeau underwent a major expansion and modernization designed to increase the terminal's capacity and substantially enhance the level of passenger service.

It contains an underground train station that was planned to eventually connect the airport with downtown Montreal as well as ADM's corporate headquarters.

On the same day, Montreal–Trudeau airport opened the doors to the refurbished, expanded, modernized and user-friendly transborder terminal, meeting the industry's highest standards.

Furthermore, the terminal is equipped with a new baggage sorting room which allows U.S. customs officers to retrieve luggage for secondary inspection.

[citation needed] In July 2011, James Cherry, the CEO of Aéroports de Montréal, announced the construction of a two-phase expansion of Montréal–Trudeau's international terminal.

It was conceived by Humà Design and integrates three massive art installations and four vitrines showcasing Montreal's museums.

This area is called Haltes gourmandes (English: gourmet stops) referring to the large number of restaurants located there.

[31] In January 2016, ADM published a call for tenders on their website regarding the restoration and upgrade of the curtain wall of the main façade on the terminal.

Also, according to the 2013–2033 master plan from ADM, the following future developments are in the works: On April 30, 2018, a massive new expansion project was unveiled that will last until 2030.

Works throughout the airport include showcases, illuminated columns, temporary exhibitions in the international arrival complex and permanent collection from various artists from the city.

The airport has eight mobile lounges that are used to shuttle passengers from the terminal to a plane parked at a remote hardstand spot.

At the far end of the jetty, there is a wide open space with a lot of natural lights through floor to ceilings windows and a big skylight in the rooftop.

A rest area has been constructed near gate 57 in order to read these books in a calm environment, with cushions and dimmed lights.

If needed, some gates can be isolated in order to offer additional security checkpoints if an aircraft flies to a potential risk zone like Washington–National.

^A : At Montréal–Trudeau and at other airports in Canada with United States border preclearance, a distinction is made between "transborder" and "international" flights for operational and statistical purposes.

^B : During 2020 & 2021, there was a significant decrease of passenger numbers due to the COVID-19 global pandemic and Canada border closures and/or restrictions.