St. Helena Island is a Sea Island in Beaufort County, South Carolina, United States. The island is connected to Beaufort by U.S. Highway 21. The island has a land area of about 64 sq mi and a population of 8,763 as of the 2010 census. It is included as part of the Hilton Head Island-Beaufort Micropolitan Area. The island is renowned for its rural Lowcountry character and being a major center of African-American Gullah culture and language.