Shawneetown is a city in Gallatin County, Illinois, United States. The population was 1,054 at the 2020 United States Census. It is the cou…Shawneetown is a city in Gallatin County, Illinois, United States. The population was 1,054 at the 2020 United States Census. It is the county seat of Gallatin County. Shawneetown is located southeast of the center of Gallatin County at 37°42′53″N 88°11′00″W / 37.714701°N 88.183465°W. Illinois Route 13 passes through the city, leading southeast 3 miles to the Ohio River and the Kentucky border at Old Shawneetown, and west 20 miles to Harrisburg. It is located at the northeast edge of Shawnee National Forest.