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.

Oxford is the 14th most populous city in Mississippi, and the county seat of Lafayette County, 75 miles (121 km) southeast of Memphis. A college town, the University of Mississippi or "Ole Miss" is adjacent to the city. Founded in 1837, it is named for Oxford, England.