The Toronto subway is a system of three underground, surface, and elevated rapid transit lines in Toronto and Vaughan, Ontario, Canada, operated by the Toronto Transit Commission (TTC). It was the country's first subway system: the first line was built under Yonge Street with a short stretch along Front Street and opened in 1954 with 12 stations. Since then, the system has expanded to become Canada's largest in terms of number of stations and its second-busiest, with an average of 915,000 passenger trips each weekday recorded during the fourth quarter of 2017.^[1] There are a total of 70 operating stations with an additional 60 under construction – 28 of which will be street-running light rail transit (LRT) stops – and 5 former stations.

The subway system encompasses three lines and 70 stations on 70.5 kilometres (43.8 mi) of route.^[2] As of December 2023^[update], 55 of the 70 stations are accessible, with plans to ensure all stations are accessible by 2025.^[3] Line 3 Scarborough, a light metro line with six stations, was permanently closed in July 2023.

As of August 2023,^[update] three new lines are under construction, two light rail lines and one light metro line:

• Line 5 Eglinton, a 25-station, 19-kilometre (12 mi) line along Eglinton Avenue, scheduled to open in 2024. A 9.2-kilometre (5.7 mi) extension of the line westwards is also under construction, scheduled to open in the early 2030s.^[4]
• Line 6 Finch West, a 18-stop, 11-kilometre (6.8 mi) line along Finch Avenue West, scheduled to open in 2024.^[5]
• Ontario Line, a 15-station, 15.6-kilometre (9.7 mi) line from Exhibition station to Science Centre station, scheduled to open in the 2030s.^[6]

• Toronto subway public art