Washington County is in Southern Illinois. Of the 102 counties in the Land of Lincoln, Washington County ranks 46th in terms of size (360,901 acres). Recent listings of residential land and property for sale in Washington County, Illinois, totals 1,000 acres and a combined market value of approximately $4 million. By overall acreage, house is the most common type of land for sale in Washington County. The average price of residential acreage for sale in Washington County was $292,571. 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.