Hutchinson Island South is a census-designated place (CDP) on the barrier island of Hutchinson Island in St. Lucie County, Florida, United States. The South in its name refers to its location in the southern part of St. Lucie County, as it is actually in the central part of the island as a whole. The population was 4,846 at the 2000 census. It is part of the Port St. Lucie Metropolitan Statistical Area. Its mail is delivered from Jensen Beach 34957 in nearby Martin County. The Jensen Beach post office has a postal contract substation known as Hutchinson Beach located at 11007 South Ocean Drive, but it offers only post office boxes and counter services.GeographyHutchinson Island South is located at .According to the United States Census Bureau, the CDP has a total area of 48.1sqmi, of which 4.5sqmi is land and 43.6sqmi is water.TransportationThe primary road is South Ocean Drive, which is also known as State Road A1A and passes from north to south through the community.DemographicsAs of the census of 2010, there were 5,201 people, 2,827 households, and 1,749 families residing in the CDP. The population density was 1,074.1 people per square mile (414.9/km²). There were 5,889 housing units at an average density of 1,305.3/sq mi (504.2/km²). The racial makeup of the CDP was 98.95% White, 0.14% African American, 0.12% Native American, 0.23% Asian, 0.10% from other races, and 0.45% from two or more races. Hispanic or Latino of any race were 0.89% of the population.