Ontario Highway 45

King's Highway 45
Northumberland County Road 45 Peterborough County Road 45
Highway 45 highlighted in red
Route information
Maintained by Ministry of Transportation of Ontario
Length	54.1 km[1] (33.6 mi)
Existed	September 1, 1937[2]–January 1, 1998[3]
Major junctions
South end	Highway 2 (King Street) in Cobourg
Major intersections	Highway 401 (Exit 474) – Toronto, Kingston
North end	Highway 7 in Norwood
Location
Country	Canada
Province	Ontario
Counties	Northumberland County, Peterborough County
Towns	Cobourg, Baltimore, Hastings, Norwood
Villages	Fenella, Alderville, Roseneath
Highway system
Ontario provincial highways Current Former 400-series
← Highway 44 → Highway 46

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.

Established in 1937 along existing county roads, the highway generally maintained the same route throughout its existence, aside from minor realignments. In 1997, it was downloaded and transferred to the counties of Northumberland and Peterborough, both of which designated it as County Road 45.