Ontario Highway 4

highway in Ontario

King's Highway 4, also known as Highway 4, is a provincial highway in Ontario, Canada. It starts at Highway 3 in Southwold. It then continues northward until ending at Highway 8 in Clinton. It is 100.8 kilometers (62.6 miles) long. The highway passes through Elgin County, Middlesex County, and Huron County. It also passes through the major cities of St. Thomas and London.

Highway 4 shield

Highway 4
Location of Highway 4 in Southern Ontario
     Current route      Former route
Route information
Length100.8 km (62.6 mi)
ExistedFebruary 26, 1920[1]–present
Major junctions
South end Highway 3 – St. Thomas
  Highway 401
 Highway 402
 Highway 7
North end Highway 8 – Clinton
Major citiesSt. Thomas, London
TownsExeter, Clinton
Highway system
Highway 3Highway 5
Former provincial highways
←  Highway 3B Highway 4A  →


  1. Shragge 1984, p. 74.