Seabrook Island is a town in Charleston County, South Carolina, United States. The population was 1,250 at the 2000 census. As defined by the U.S. Census Bureau, Seabrook Island is included within the Charleston-North Charleston Metropolitan Statistical Area. Seabrook Island apartments for rent comparison page shows most up to date rent information on Seabrook Island apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.