London is a city in and the county seat of Madison County, Ohio, United States. Located about 25 miles (40 km) southwest of the Ohio capital of Columbus, London was established in 1811 to serve as the county seat. The population was 9,904 at the 2010 census. The ZIP code is 43140.
Soon after the village was platted in the early 1810s, a Methodist church was founded in the community. Today known as First United Methodist Church, this congregation built a small log church building in 1820; it was London's first church. In the early 1900s, the church added facilities for the storage of human milk to sustain the orphanage it then operated.
London is the county seat of Madison County, Ohio. Patrick McLene established the community in 1810 or 1811, on land owned by John Murfin. It is unclear why residents named the town London. Many people believe that residents, many of whom were from Great Britain, named the town after London, England.