The current orchestra directly traces its roots back to 1934, when Wilfrid Pelletier formed an ensemble called Les Concerts Symphoniques.

In the early 1960s, as the Orchestra was preparing to move to new facilities at Place des Arts, patron and prominent Montreal philanthropist, John Wilson McConnell, purchased the 1727 Laub-Petschnikoff Stradivarius violin for Calvin Sieb, the Symphony's concertmaster.

In addition, Frühbeck de Burgos was quoted in print in La Presse as expressing public criticism of selected OSM musicians.

The OSM won Grammy awards in 1996 for its recording of Hector Berlioz' Les Troyens and in 2000 for Sergei Prokofiev and Béla Bartók piano concerti with Martha Argerich on EMI.

In 1998, OSM musicians took strike action for three weeks that was resolved largely due to the personal relationship between Dutoit and Lucien Bouchard, then the premier of Quebec.

Later in 2005, the OSM's musicians took industrial action, where this work stoppage lasted five months, ending shortly before Nagano's first scheduled concerts.

[8][9] Nagano concluded his OSM music directorship at the close of the 2019-2020 season, with the scheduled final concerts of his tenure curtailed by the COVID-19 pandemic.

In 2018, the orchestra toured several Cree and Inuit communities in Nord-du-Québec to perform Chaakapesh: The Trickster's Quest, an indigenous opera by Tomson Highway and Matthew Ricketts.

[14] Additional work by the OSM has included a collaboration with Les Cowboys Fringants on the 2023 live album En concert avec l’Orchestre symphonique de Montréal (sous la direction du chef Simon Leclerc), which won the Juno Award for Francophone Album of the Year at the Juno Awards of 2024.