King's Highway 45, commonly referred to as Highway 45, was a provincially maintained highway in the Canadian province of Ontario. The 54.1-kilometre-long (33.6 mi) route connected Highway 2 in downtown Cobourg with Highway 7 in Norwood. In addition to the towns at either end, it bisected the communities of Baltimore, Fenella, Alderville, Roseneath and Hastings.

King's Highway 2, commonly referred to as Highway 2, is the lowest-numbered provincially maintained highway in the Canadian province of Ontario, and was originally part of a series of identically numbered highways which started in Windsor, stretched through Quebec and New Brunswick, and ended in Halifax, Nova Scotia. Prior to the 1990s, Highway 2 travelled through many of the major cities in Southern Ontario, including Windsor, Chatham, London, Brantford, Hamilton, Burlington, Mississauga, Toronto, Oshawa, Belleville, Kingston and Cornwall, and many other smaller towns and communities.