Jackson County is a county located in the U.S. state of Mississippi. As of the 2010 census, the population was 139,668, making it the fifth-most populous county in Mississippi. Its county seat is Pascagoula. The county was named for Andrew Jackson, general in the United States Army and afterward President of the United States. Jackson County is included in the Gulfport-Biloxi-Pascagoula, MS Metropolitan Statistical Area.