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.
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.
London, Ohio