The Montréal-Pierre-Elliott-Trudeau International Airport is located in the Montréal suburb of Dorval. Therefore, you will need to get downtown by your own means. We suggest you take the airport shuttle, L’Aérobus, that will bring you straight from the airport to downtown Montréal. The shuttle will drop you off at the Montréal Central Bus Station (505, de Maisonneuve Est) which is served by the Berri-UQAM métro station. A minibus service at no additional charge is also available from the Montréal Central Bus Station to several major downtown hotels (reservation: 514-631-1856). The price of the shuttle for a round-trip is $22.75 CAD.
You could also take a taxi, which, depending on the traffic, will cost you anywhere starting from $34.75 CAD.