The following is a list of the major roads in London, a major city in Southwestern Ontario. The city is organized in a grid pattern that dates back to the early 19th century, where it is based on the former Townships of London and Westminster. Many roads follow a typical grid pattern, while others follow an alignment along certain bodies of water such as the Westminster Ponds and Thames River. Each geographical township's layout of roads are different. This has led to jogs in the road network, most of which have since been corrected.