James Island is one of South Carolina's most urban Sea Islands; nearly half of the island sits within Charleston city limits. The island is separated from peninsular downtown Charleston by the Ashley River, from the mainland by Wappoo Creek and the Wappoo Cut, and from Johns Island by the Stono River. It lies inshore of Morris Island and Folly Beach.

Johns Island is an island in Charleston County, South Carolina, United States, and is the largest island in the state of South Carolina. Johns Island is bordered by the Wadmalaw, Seabrook, Kiawah, Edisto, Folly, and James islands; the Stono and Kiawah rivers separate Johns Island from its border islands. It is the fourth-largest island on the US east coast, surpassed only by Long Island, Mount Desert Island and Martha's Vineyard. Johns Island is 84 square miles (220 km2) in area, with a population of 21,500.