Ontario Highway 27

King's Highway 27, commonly referred to as Highway 27, is a provincially maintained highway in the Canadian province of Ontario. The Ministry of Transportation of Ontario was once responsible for the length of the route, when it ran from Long Branch to Highway 93 in Waverley. Highway 27 followed a mostly straight route throughout its length, as it passed through the suburbs of Toronto, then north of Kleinburg the vast majority of the highway was surrounded by rural farmland. Today, only the southernmost one mile (1.6 km) from Highway 427 north to Mimico Creek is under provincial jurisdiction, the remainder of the route is maintained by the city of Toronto, York Region and Simcoe County.

Highway 27 was created in 1927, connecting Barrie with Penetanguishene. It was extended south to Schomberg in 1934, and later to Toronto by the late 1930s. Between Barrie and Toronto, the route served as a redundancy to Highway 11 (Yonge Street), and later Highway 400. Through the 1950s, the portion of Highway 27 between Evans Avenue and north of Eglinton Avenue was expanded into a four-laned dual highway known as the Toronto Bypass (which included portions of the new Highway 401 through Toronto). Beginning in the mid-1960s, this dual highway was expanded into the current collector–express system and renumbered as Highway 427 upon completion at the end of 1971. The majority of the remainder of the route was decommissioned in the late 1990s; the majority of the former highway is now designated and signed as York Regional Road 27 and Simcoe County Road 27.