Some of the cities, towns, and places in Williamson County are Attila, Blairsville, Bush, Cambria, Carbondale, Carterville, Chamness, Clifford, Colp, Corinth, Crab Orchard, Crainville, Creal Springs, Crenshaw, Dewmaine, Dog Walk, Dykersburg, East Marion, Energy, Fergestown, Franklin County, Freeman Spur, Grassy, Halfway, Halfway (Little Juarez), Herrin, Hudgens, Hurst, Jackson County, Johnson County, Johnston City, Lake Creek, Marion, New Dennison, No. 9, Paineville, Palzo, Paulton, Pittsburg, Pulleys Mill, Saline County, Southern, Spillertown, Stiritz, Stonefort, West Marion, Whiteash, Willeford
Williamson County is a county in Southern Illinois. At the 2020 census, it had a population of 67,153. The largest city and county seat is Marion.Williamson County is included in the Carbondale-Marion, IL Metropolitan Statistical Area. This area of Southern Illinois is known locally as "Little Egypt".Williamson is in the Metro Lakeland area, 88 miles (142 km) southeast of St. Louis, Missouri. Via the nearby intersection of Interstates 57 and 24, and Illinois Route 13, a primary east–west four-lane expressway, the city has access to the major communities of Murphysboro, Carbondale, Carterville, Herrin, Marion and Harrisburg.
The Metro Lakeland area of Jackson-Williamson counties has a total of 120,000 residents. Carbondale (14 miles west), Herrin and Marion are the key urban areas in Metro Lakeland, with a combined population of more than 65,000. Over 235,000 people live within 35 miles (56 km).