Jefferson Davis County is a county located in the U.S. state of Mississippi. As of the 2020 census, the population was 11,321. Its county seat is Prentiss. The county is named after Mississippi Senator and Confederate President Jefferson Davis. The county was carved out of Covington and Lawrence counties in March 1906. Governor James K. Vardaman signed the bill creating the county on May 9, 1906.

Prentiss is a town in Jefferson Davis County, Mississippi, United States. The population was 1,081 at the 2010 census, down from 1,158 at the 2000 census. It is the county seat.