Metrolinx is a Crown agency of the Government of Ontario that manages and integrates road and public transport in the Greater Toronto and Hamilton Area (GTHA), which comprises much of Ontario's Golden Horseshoe region. Headquartered at Union Station in Toronto, the agency was created as the Greater Toronto Transportation Authority on June 22, 2006. The agency adopted its present name as a brand name in 2007 and eventually as the legal name in 2009.

Crown corporations in Canada are government organizations with a mixture of commercial and public-policy objectives. They are directly and wholly owned by the Crown.