Ontario Highway 4
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.
|Length||100.8 km (62.6 mi)|
|Existed||February 26, 1920–present|
|South end||Highway 3 – St. Thomas|
| Highway 401|
|North end||Highway 8 – Clinton|
|Major cities||St. Thomas, London|