Leonardsville is a hamlet on the Unadilla River in the Town of Brookfield in Madison County, New York, United States. The community started as a number of small factories deriving power from a dam on the Unadilla River during the first decade of the 19th century. These were known locally as the shops and included a scythe and hoe factory, a blacksmith shop, a grist mill, a saw mill, a horse rake factory and wagon shop, and a foundry and machine shop. The Wheeler House Complex was listed on the National Register of Historic Places in 1983.