Sponsored Topics. Murphysboro is a city in and the county seat of Jackson County, Illinois, United States. The population was 7,970 at the 2010 census. The city is part of the Metro Lakeland area. Murphysboro is located at 37°46′2″N 89°20′14″W / 37.76722°N 89.33722°W / 37.76722; -89.33722 (37.767245, -89.337346).