Chillicothe is a city in Hardeman County, in the U.S. state of Texas. The population was 798 at the 2000 census. The population was 707 at the 2010 census.The historic preservationist Myna Potts resides in Chillicothe. She is curator of the Medicine Mound Museum, a restoration of her late father's general store in the ghost town of Medicine Mound, located 9 miles south of Chillicothe.