English English Wikipedia has an article on:Williamson CountyWikipedia Pronunciation Rhymes: -aʊnti Proper noun Williamson County One of 102 counties in Illinois, United States. County seat: Marion. Named after the county in Tennessee. One of 95 counties in Tennessee, United States. County seat: Franklin. Named after Hugh Williamson. One of 254 counties in Texas, United States. County seat: Georgetown. Named after Robert McAlpin Williamson.Wikiwand - on Seamless Wikipedia browsing. On steroids.