Beaufort County is a county in the U.S. state of South Carolina. As of the 2010 census, its population was 162,233. Its county seat is Beaufort. Beaufort County is part of the Hilton Head Island-Bluffton-Beaufort, SC Metropolitan Statistical Area. Beaufort County is one of the South's fastest-growing counties,https://www.census.gov/popest/data/counties/totals/2015/ primarily because of development south of the Broad River clustered along the U.S. Highway 278 corridor.