The 503 Kingston Rd is an east–west Toronto streetcar route in Ontario, Canada, operated by the Toronto Transit Commission. The 503 Kingston Rd travels on a route to the downtown financial district from the Bingham Loop along Kingston Road and shares much of its track with the 501 Queen and 504 King. Originally a rush-hour service, the route was upgraded in September 2019 to run weekdays excluding evenings after the consolidation of 502 Downtowner service into this route.