Wilmington Island is an unincorporated community and census-designated place (CDP) in Chatham County, Georgia. The population was 15,129 at the time of the 2020 U.S. census. It is part of the Savannah metropolitan area. The communities of Wilmington Island form a large and affluent suburb of Savannah, where most residents work. The island lies east of Savannah between the town of Thunderbolt and the beach city of Tybee Island.

Chatham County is located in the U.S. state of Georgia, on the state's Atlantic coast. The county seat and largest city is Savannah. One of the original counties of Georgia, Chatham County was created February 5, 1777, and is named after William Pitt, 1st Earl of Chatham.