Whiteside County is in Northern Illinois. Of the 102 counties in the Land of Lincoln, 696-square-mile Whiteside County ranks 27th by size. There is nearly 1,000 acres of residential land for sale in Whiteside County, Illinois, based on recent Land Network data, making it the most common type of land for sale in Whiteside County. The combined market value of land for sale here is around $6 million. The average price of residential acreage for sale in Whiteside County was $306,854. 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.