The Société de transport de Montréal is a public transport agency that operates transit bus and rapid transit services in the urban agglomeration of Montreal, Quebec, Canada. Established in 1861 as the "Montreal City Passenger Railway Company", it has grown to comprise four subway lines with a total of 68 stations, as well as 212 bus routes and 23 night routes. The STM was created in 2002 to replace the Société de transport de la communauté urbaine de Montréal. The STM operates the most heavily used urban mass transit system in Canada, and one of the most heavily used rapid transit systems in North America. As of 2019, the average daily ridership is 2,297,600 passengers: 977,400 by bus, 1,306,500 by rapid transit and 13,700 by paratransit service.

The Montreal Metro is a rubber-tired underground rapid transit system serving Greater Montreal, Quebec, Canada. The metro, operated by the Société de transport de Montréal (STM), was inaugurated on October 14, 1966, during the tenure of Mayor Jean Drapeau.