Warren County is in Western Illinois. Of the 102 counties in the state, 543-square-mile Warren County ranks 49th by size. There is almost 1,000 acres of residential land and property for sale in Illinois's Warren County based on recent Land Network data, making it the most common type of land for sale in Warren County. The combined market value of farms and rural land for sale here is about $3 million. The average price of residential acreage for sale in Warren County was $267,980. 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.