Lafayette County is a county in the U.S. state of Mississippi. At the 2020 census, the population was 55,813. Its county seat is Oxford. The local pronunciation of the name is "la-FAY-et." The county's name honors Marquis de Lafayette, a French military hero and American general who fought during the American Revolutionary War. The Oxford, MS Micropolitan Statistical Area includes all of Lafayette County. The county is policed by the Lafayette County Sheriff's Department.