Mannsville is a town in Johnston County, Oklahoma, United States. The population was 587 at the 2000 census.Mannsville is located at 34°11′9″N 96°52′49″W / 34.18583°N 96.88028°W / 34.18583; -96.88028.According to the United States Census Bureau, the town has a total area of 1.1 square miles, of which, 1.1 square miles of it is land and 0.92% is water. They have a fully staffed Fire Department made up of all volunteers with 3 stations, two in town and one out on in the small community of Greasy Bend.As of the census of 2000, there were 587 people, 221 households, and 150 families residing in the town. The population density was 543.8 people per square mile. There were 253 housing units at an average density of 234.4 per square mile. The racial makeup of the town was 81.77% White, 0.17% African American, 9.88% Native American, 0.34% from other races, and 7.84% from two or more races. Hispanic or Latino of any race were 0.51% of the population.There were 221 households out of which 33.