Lexington is a city in and the county seat of Holmes County, Mississippi, United States. The county was organized in 1833 and the city in 1836. The population was 1,731 at the 2010 census, down from 2,025 at the 2000 census. The estimated population in 2018 was 1,496. It has declined from its high of 3,198 in 1950 due to the expansion of industrial-scale agriculture.