The 508 Lake Shore was an east-west streetcar route in Toronto, Ontario, Canada, operated by the Toronto Transit Commission from 1995 to 2015. The route served the downtown financial district from the western limit of the city, and operated as a weekday rush hour service only. The route shared much of its track with the 501 Queen and 504 King routes, following in the path of the 501 from the Long Branch Loop along Lake Shore Boulevard West and The Queensway as far as Roncesvalles Avenue, where it turned from Queen Street on to 504 King Street tracks. The route terminated at Parliament St in the morning, and originated at Church Street in the afternoon.
At the time of its cancellation, there were only three eastbound trips during the morning rush hour, and no service in the afternoon. Prior to January 2015 there were also four westbound trips in the afternoon rush hour.
Due to a shortage of streetcars caused by the delayed deliveries of the TTC's new wheelchair-accessible Flexity Outlook streetcars, the route ceased operations entirely after the morning rush on June 19, 2015. As a result, streetcar service on Lake Shore Boulevard is now operated exclusively by the 501 Queen streetcar, while service on King street is operated by the 504 King streetcar.