Kemper County is a county located on the central eastern border of the U.S. state of Mississippi. As of the 2020 census, the population was 8,988. Its county seat is De Kalb. The county is named in honor of Reuben Kemper. The county is part of the Meridian, MS Micropolitan Statistical Area. In 2010 the Mississippi Public Service Commission approved construction of the Kemper Project, designed to use "clean coal" to produce electricity for 23 counties in the eastern part of the state.