Williamson County is in Southern Illinois. Of the 102 counties in the Prairie State, Williamson County ranks 65th in terms of size (444 square miles). The total value of almost 1,000 acres of farms recently listed for sale in Williamson County, Illinois, was almost $3 million. The average price of farmland for sale in Williamson County was $643,375. Farms for sale in Williamson County sustain livestock including horses, cattle, goats, sheep and pig. Browse all Illinois farms for sale on the Land Network to find the farm, cattle operation, hobby farm or other farm property that's right for your future commercial or individual needs.