The Blue Line (, ), also known as Line 5 (), is one of the four lines of the Montreal Metro in Montreal, Quebec, Canada. It was the fourth to be built, notwithstanding its alternate official name of "Line 5", as Line 3 was planned but never built. Unlike the other three routes, the east–west Blue Line does not serve the city's main Metro junction at Berri–UQAM.
The line first opened in 1986, with the last addition to the line being an intermediate station in 1988. The line is currently being extended five stations to the east, with completion scheduled for 2031.
History
The Blue Line was first proposed in the early 1970s as an east–west line passing through the centre of the island of Montreal. , the line has similar opening hours to other metro lines. , four stations on the line are accessible, including both interchange stations at Snowdon and Jean-Talon. In the 2020s, the renovation of Édouard-Montpetit station included linking the station to the new Réseau express métropolitain, which replaced the Deux-Montagnes line with rapid transit.
In January 2023, the Société de transport de Montréal announced that the line would be re-signalled with communications-based train control (CBTC) as part of the work to extend the line eastwards to Anjou. In February 2024, a $217-million contract was awarded to Thales to install CBTC on the line.
Extensions
Initial proposals for the line in the 1970s suggested that the line would run from Ville Saint-Pierre, Lachine, in the west, passing through the centre of the island of Montreal before turning north towards Montréal-Nord.
Eastern extension to Anjou
Following the opening of the line in the 1980s, various governments have proposed extending the line east to Anjou, such as prior to the provincial elections of 1989. The terminus would be located at the Galeries d'Anjou shopping centre, near the junction of Autoroute 25 and Autoroute 40.
On 20 September 2013, a extension northeast to St. Leonard and Anjou was announced by the STM and the Quebec government. The provincial government announced that the extension would proceed and committed $38.8 million to set up a project office tasked with preparing detailed financial and technical plans within two years. The start of construction was slated for 2021, with completion in 2025.
After the Parti Québécois lost the 2014 provincial election, the future of the Blue Line extension came into question. The successor Liberal government had expressed interest in extending mass transit to Montréal–Trudeau International Airport and implementing a light rail line on the new Champlain Bridge under construction. On 28 May 2014, it was announced that the project would be reviewed by the new provincial government and that, if the project was again approved, construction would start in 2021, which was confirmed in the STM's new 2025 Plan.
On 9 April 2018, premier of Quebec Philippe Couillard and Prime Minister Justin Trudeau announced their commitment to fund and complete the extension, then planned to open in 2026. Around $365 million was provided to STM to allow them to purchase land and undertake design and technical work. In March 2025, the federal government committed an additional $650 million to the project. The extension was set to include five new stations, two bus terminals, a pedestrian tunnel connecting to the Pie-IX BRT and a new park-and-ride. Overall, the project was estimated to cost around $5.8 to $6.4 billion and scheduled to be completed in 2029.
Initial construction work began in August 2022. Procurement work to build the tunnels and stations began in the fourth quarter of 2022. In September 2023, construction tenders for the tunnel boring machine were called and an announcement was made that the opening date would be delayed to 2031. In February 2024, Thales was awarded a CA$217 million contract to install communications-based train control on the Blue Line, including on the new extension. In August 2024, a consortium led by Pomerleau was awarded a CA$1.1 billion contract to dig the tunnel and construct 3 stations. It was also announced that the extension would now cost CA$7.6 billion to construct. It was estimated that around 69,000 daily passengers would use the extension. In March 2025, the federal government announced that it would contribute a further CA$650 million towards the extension. In September 2025, Mayor of Montreal Valérie Plante announced the names of the five new stations, with several stations named after women. In October 2025, a tunnel boring machine that would dig the extension arrived from Germany. Digging, which will advance at a rate of ten metres per day is projected to begin in April 2026. The tunnel boring machine name was revealed in May 2026 as "Lisette" in honor of the first female metro operator of the STM, following a public vote.
Proposed western extension
The original intent for the Blue Line was that it would extend southwest from Snowdon to serve Notre-Dame-de-Grâce, Hampstead, Montreal West and Ville Saint-Pierre. Snowdon station was constructed with a cross-platform interchange to allow easy access to Orange line trains heading downtown. Trains arrive at stations every 3 to 6 minutes during peak periods, every 4 to 10 minutes during off peak periods, and every 8 to 10 minutes on weekends.