London is a city in Madison County, Ohio, United States. It was established in 1810 to serve as the county seat of Madison County. As of the 2000 census, the city population was 8,771, an increase from 7,807 in 1990. A 2006 estimate placed the population at 9,496, as suburban sprawl from neighboring Columbus continues. The ZIP code is 43140. London apartments for rent comparison page shows most up to date rent information on London apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.