McCowan Yard is an inactive rail yard on the Toronto Transit Commission's (TTC's) Line 3 Scarborough of the Toronto subway system. Line 3 permanently closed following a derailment on July 24, 2023.^[2]

McCowan Yard is situated on a 4.5-acre (1.8 ha) site located east of McCowan Station, the eastern terminal of the former Line 3. The yard's street entrance is at 1720 Ellesmere Road, Scarborough, Toronto.^[1]

The yard provided facilities for the storage, cleaning, and maintenance of the 28 Intermediate Capacity Transit System (ICTS) vehicles used on Line 3 Scarborough.^[3] The yard employed a staff of 40.^[1]

The yard had a carhouse made of prefabricated metal designed by the TTC's Engineering and Construction Department.^[1] The carhouse contained one wash track and two repair/maintenance tracks. Outside, there were four storage tracks for passenger vehicles^[3] and a turning loop of 70 ft (21 m) radius was used to store work vehicles.^[4] The yard also had a power substation.^[5]

McCowan Carhouse was limited to light repairs and maintenance. Major maintenance work had to be performed at the Greenwood Yard shop. Because of gauge and technology differences, ICTS cars had to be transported by truck between the McCowan and Greenwood yards.^[3][5]

McCowan Yard was to have been a temporary facility pending an expansion of the line to Malvern.^[3][5] However, the City of Toronto has decided to replace Line 3 with an extension of Line 2 Bloor–Danforth estimated to open in 2030.^[6] Thus, with the closure of Line 3, McCowan Yard has been shut down and will be decommissioned.