Lone Oak (also Browns Chapel or Top of the Mountain) is an unincorporated community and census-designated place (CDP) in southern Sequatchie County, Tennessee, United States. It lies along U.S. Route 127 south of the city of Dunlap, the county seat of Sequatchie County. Its elevation is 2001 ft. As of the 2020 census, its population was 1,198, down from 1,206 at the 2010 census.