Jefferson County is in Southern Illinois. Of the 102 counties in the Land of Lincoln, 373,648-acre Jefferson County ranks 41st by size. The most common type of land for sale by combined acreage in Jefferson County is house. Browse all waterfront property for sale in Jefferson County on the Land Network to find the marina, lakefront and other recreational property that meets your needs, from waterside land perfect as a retirement investment to existing residential waterfront land and property for hunting, fishing and other outdoor-recreation pursuits!