Line 3 Scarborough, originally known as Scarborough RT (SRT), was a medium-capacity rapid transit line that was part of the Toronto subway system of the Toronto Transit Commission in Toronto, Ontario, Canada. The line ran entirely within the eastern district of Scarborough, encompassing six stations and 6.4 kilometres (4.0 mi) of mostly elevated track. It was connected with Line 2 Bloor–Danforth at its southwestern terminus, Kennedy, and terminated in the northeast at McCowan. Until its closure in July 2023, the system had a ridership of 4,720,000 passengers per year.