Dauphin Island, is an island town in Mobile County, Alabama, United States, on a barrier island of the same name in the Gulf of Mexico. It was incorporated in 1988. The population was 1,778 at the 2020 census, up from 1,238 at the 2010 census. The town is part of the Mobile metropolitan area. The island was renamed for the king Louis XIV's great-grandson and heir, the dauphin, the future king Louis XV. The name of the island is often mistaken as Dolphin Island; the word dauphin is French for 'dolphin', but historically the term was used as the title of the heir apparent to the French monarch.