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, passing through the Greater Toronto Area (GTA) (although bypassing Toronto proper), and on 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 GTA to county and regional jurisdiction. The highway is now long; the western segment begins at Highway 4 north of London and extends to Georgetown in the GTA, while the eastern segment begins at Donald Cousens Parkway in Markham and extends to Highway 417 in Ottawa.
Highway 7 was first designated in 1920 between Sarnia and Guelph and extended to Brampton the following year. Between 1927 and 1932, the highway was more than doubled in length as it was gradually extended eastward to Perth, where Highway 15 continued to Ottawa via Carleton Place. In the early 1960s, that section of Highway 15 was renumbered as Highway 7. In that same decade, the Conestoga Parkway through Kitchener and the Peterborough Bypass were constructed. During the 1970s and 1980s, many sections of Highway 7 were widened from the initial two lane cross-section to four or six lanes. Within central York Region, where it would share a narrow corridor with the then-future Highway 407, the route was upgraded to a limited-access, suburban arterial expressway in preparation for the construction of the latter route.
Soon thereafter, that new tollway would act as justification for transferring the section of Highway 7 through the GTA to regional governmentsdespite the fact that the western terminus of the 407 is at the junction of the Queen Elizabeth Way and Highway 403 in Burlington; too far south to provide any continuity with Highway 7, and also that the highway could have remained intact as a municipally-maintained connecting link as is typically the case where a through-highway traverses an urban area. The sections became Peel Regional Road 107 (following Bovaird Drive and Queen Street from west and east of Highway 410 respectively), and York Regional Road 7. In the west, the construction of Highway 402 between Sarnia and London provided an uninterrupted alternative to Highway 7, resulting in the transfer of the section west of Highway 4. A third transfer took place in Peterborough, briefly separating the route into three discontinuous segments, but has since been rectified by renumbering a section of Highway 7A. From 2007 to 2012, the section of Highway 7 between Carleton Place and Ottawa has been widened to a divided freeway. In addition, work is underway to extend the Conestoga Parkway to New Hamburg as well as to build a new freeway between Kitchener and Guelph.
The speed limit is for the freeway portion between Carleton Place and Highway 417 and the section running concurrent with Highway 115, and ranges from to elsewhere. The route is patrolled by the Ontario Provincial Police (OPP) and maintained by the Ministry of Transportation of Ontario (MTO).
Route description Originally, Highway 7 extended as far west as Sarnia, remaining as a provincial highway for some time after the completion of the extension of Highway 402 to London. At Warwick, Highway 7 crosses Highway 402, west of that point these routes ran parallel to each other for 40 km (both roads never being further than 2 kilometres apart) until Highway 40. Upon entering the Sarnia city limits from the east on Highway 7, drivers encountered a plethora of motels and restaurants, the Sarnia Airport, and attractions such as Hiawatha Racetrack and Waterpark, earning the stretch between Modeland Road and Airport Road the nickname of the "Golden Mile". The interchange with Highway 40 marked the former western terminus of Highway 7, thereafter the road continues as Exmouth Street as the opposing carriageways merge and follow an S-curve before passing Lambton Mall. Since being downloaded to municipal authorities, the former highway is now known as Lambton County Road 22 (London Line) and Middlesex County Road 7 (Elginfield Road).
Western segment The current western segment of Highway 7 travels from Elginfield in Middlesex County in the southwest to the Halton–Peel border at Norval near Brampton, situated in the Greater Toronto Area; a distance of . The western segment was separated from the rest of Highway 7 on June 7, 1997, when the section from Brampton to Markham was downloaded due to the opening of Highway 407. A portion of this segment, from Waterloo Regional Road 51 south of Baden to Highway 85 in Kitchener is a freeway, forming part of the Conestoga Parkway. Plans to build a freeway bypass of Highway 7 from Kitchener to Guelph are currently underway (see below).
The current route begins at Highway 4, approximately north of London and immediately southeast of the village of Lucan; the former routing continued west along Elginfield Road through Parkhill and Arkona. Though the highway changes direction several times between Elginfield and Kitchener, it is mostly straight and two lanes wide, except east of New Hamburg where it widens to four lanes. Proceeding east-northeast through farmland, the highway meets the southern terminus of Highway 23 after . It continues, serving as the boundary between Lucan Biddulph to the north and Middlesex Centre to the south, and later as the boundary between Perth County to the north and Middlesex and Oxford counties, with the tripoint of the three at County Road 120A south of St. Marys. Southeast of St. Marys, Highway 7 curves northeast into Perth County until it reaches downtown Stratford, where it meets Highway 8.
The two highways travel east concurrently for , passing through the town of Shakespeare as it travels in a straight line through farmland. Southwest of New Hamburg, the route curves northeast into Waterloo Region, eventually widening into the four-lane Conestoga Parkway east of Nafziger Road. It follows this divided freeway past interchanges at Waterloo Regional Road 51 (Foundry Street) south of Baden, Waterloo Regional Road 12 (Queen Street/Notre Dame Drive) south of Petersburg, and Waterloo Regional Road 70 (Trussler Road) north of Mannheim, where it enters Kitchener and becomes surrounded by residential subdivisions. Within Kitchener, Highway 7 encounters interchanges at Waterloo Regional Road 58 (Fischer-Hallman Road)(at which point it widens to six lanes), Waterloo Regional Road 28 (Homer Watson Boulevard), Waterloo Regional Road 53 (Courtland Avenue), Waterloo Regional Road 15 (King Street)/Highway 8 (at which point it widens to eight lanes), Waterloo Regional Road 14 (Ottawa Street) and Waterloo Regional Road 55 (Victoria Street). The Highway 8 concurrency ends at the King Street interchange, with it diverging southeast onto the Freeport Diversion. Highway 7 exits at Victoria Street (four-lane arterial) while the parkway continues north into Waterloo as Highway 85. Construction began in June 2015 on a future freeway between Kitchener and Guelph that will make use of a reconfigured Wellington Street interchange, just north of Victoria Street, and tie in with the northern end of the Hanlon Expressway.
Highway 7 exits Kitchener after crossing the Grand River, where it enters farmland again for the brief journey to Guelph along Victoria Street and Woodlawn Road. Midway between the two cities, the route enters Wellington County. Within Guelph, it meets Highway 6 at the northern end of the Hanlon Expressway. The two routes travel southeast along the expressway to Wellington County Road 124 (Wellington Street, former Highway 24), where Highway 7 branches northeast into downtown Guelph. It exits the city along York Road after crossing the Speed River, travelling parallel to and south of the Goderich–Exeter Railway. At Rockwood, the highway enters Halton Region (and officially the Greater Toronto Area) and begins to zig-zag through several communities in Halton Hills. These include Acton, where the route intersects former Highway 25, and Georgetown. Just east of Norval, the western section of Highway 7 ends at the Halton–Peel boundary.
Downloaded Peel-York segment
The downloaded section of Highway 7 continues into Brampton as Peel Regional Road 107 as it enters the heavily urbanized part of the GTA. Now named Bovaird Drive, it soon widens to a four-to six-lane, suburban arterial road. The former highway then follows Highway 410 south, where it continues east along Queen Street (also Peel Road 107).
Still an arterial, the former highway then enters York Region and the City of Vaughan, where it runs north of Toronto proper; its closest approach to it. East of Highway 400, it passes through Vaughan Metropolitan Centre, Vaughan's planned downtown core, which is the northern terminus of the west arm of the Toronto subway's Line 1 Yonge-University. Beyond Keele Street, it curves to the north and becomes an at-grade expressway, through the vicinity of the Vaughan, Markham, and Richmond Hill tripoint. The expressway has a speed limit of , with few traffic signals. There are grade-separated crossings of Dufferin, Bathurst, and Yonge Streets, as well as Bayview Avenue, where there is insufficient space to accommodate both intersections for them and their interchange ramps for Highway 407, which runs alongside it, and these streets are accessed by signalized L-shaped connector roads. East of Bayview, Highway 7 resumes as an arterial road along the boundary of Markham and Richmond Hill as far as Highway 404, before running solely through Markham.
Despite its urbanized arterial setting through York Region, which includes a dedicated bus rapid transit facility (the Highway 7 Rapidway) running down its centre for most of the way across the region outside the expressway section, and no longer being a provincial highway since being downloaded to municipal authorities in 1997, the road is still officially named "Highway 7". However, it otherwise has no street name, and received the number York Regional Road 7, displacing Islington Avenue which was redesignated as Regional Road 17.
The Toronto Star ran a series of articles in 2013 depicting the urbanization of the downloaded Highway 7 in the Greater Toronto Area, including a proposed name change to "Avenue 7" through York Region, although this name has not been applied as of 2025.
Eastern segment The eastern segment of Highway 7 runs from Donald Cousens Parkway (York Regional Road 48) in Markham to Highway 417 in Ottawa, a length of . Between Brooklin and north of Sunderland, Highway 7 assumes a north–south routing and is concurrent with Highway 12. The section from Sunderland to the eastern terminus of the highway is designated as part of the Central Ontario Route of the Trans-Canada Highway.
Travelling east from Donald Cousens Parkway, Highway 7 exits the urbanized portion of Markham and the GTA and enters the Greenbelt, a large tract of land north of the GTA restricted from development. It curves north at the community of Locust Hill along an alignment that eliminated a jog, then curves back to the east as it crosses into Durham Region. It travels north of and parallel to Highway 407 to Brougham, curving to cross the former eastern terminus of the freeway near Brock Road (Durham Regional Road 1). East of the Highway 407 overpass, Highway 7 widens to four lanes and curves around the community of Greenwood and the hill that it stands on. The route crosses the northern end of Pickering, entering Whitby at Lake Ridge Road (Durham Regional Road 23). Between Lake Ridge Road and Highway 12, the route was rebuilt for the new Highway 407E and West Durham Link, with an overpass constructed at Cochrane Road. East of that, the route enters Brooklin and meets Highway 12.