Port Royal is a town on Port Royal Island in Beaufort County, South Carolina, United States. Largely because of annexation of surrounding areas (including Parris Island), the population of Port Royal rose from 3,950 in 2000 to 10,678 in 2010, a 170% increase. As defined by the U.S. Census Bureau, Port Royal is included within the Hilton Head Island-Bluffton-Beaufort, SC Metropolitan Statistical Area.