The S series was the rolling stock of light metro used on Line 3 Scarborough, part of the subway system of Toronto, Ontario, Canada.

The trains use UTDC's proprietary linear motor-based Intermediate Capacity Transit System (ICTS, now branded as Bombardier Innovia Metro) and are its Mark I model, which is also used by the Vancouver SkyTrain and the Detroit People Mover.

They consist of 14 married pair sets (28 cars total) with fleet numbers 3000 to 3027, and are not compatible with the trains on other Toronto lines, which use conventional motors.

Starting in 2015, the cars underwent refurbishment, which included the addition of blue shrink wrap on their exterior to prolong their lifespan until the line's closure in 2023.

[3] In June 2024, the Detroit People Mover transit system announced the purchase of the Mark I train sets and equipment from Line 3.