Madison County is in Southwest Illinois. Of the 102 counties in the state, Madison County is 20th in terms of its size (740 square miles). Recent listings of residential land and property for sale in Illinois's Madison County totals roughly 1,000 acres and a combined market value of nearly $97 million. The most common type of land for sale by combined acreage in Madison County is residential property. The average price of residential acreage for sale in Madison County was $399,313. Browse all residential land and rural property for sale in Illinois to find residential land and properties that suit your lifestyle needs, from existing residential homes and estates to land ready for future residential-property development.