Nelsonville is a city in northwestern Athens County, Ohio, United States. The population was 5,230 at the 2000 census. Hocking College is located in Nelsonville.
Nelsonville is located at 39°27′19″N 82°13′32″W / 39.45528°N 82.22556°W / 39.45528; -82.22556 (39.455167, -82.225650), along the Hocking River; Monday Creek flows through the eastern part of the city. One of the main streets, Canal Street, is located on top of where the old Hocking Canal once ran.
According to the United States Census Bureau, the city has a total area of 5.0 square miles (12.9 km²), all of it land.