King's Highway 7, commonly referred to as Highway 7 and historically as the Northern Highway, is a provincially maintained highway in the Canadian province of Ontario. At its peak, Highway 7 measured in length, stretching from Highway 40 east of Sarnia in Southwestern Ontario to Highway 17 west of Ottawa in Eastern Ontario. However, due in part to the construction of Highways 402 and 407, the province transferred the sections of Highway 7 west of London and through the Greater Toronto Area to county and regional jurisdiction. The highway is now long; the western segment begins at Highway 4 north of London and extends to Georgetown, while the eastern segment begins at Donald Cousens Parkway in Markham and extends to Highway 417 in Kanata.