Dauphin Island is a town in Mobile County, Alabama, United States, on a barrier island of the same name (split by the Katrina Cut), at the Gulf of Mexico. It incorporated in 1988. The population was 1,238 at the 2010 census. The town is included in the Mobile metropolitan area. The island (originally named "Massacre Island") was renamed for Louis XIV of France's great-grandson and heir, the dauphin, the future Louis XV of France. The name of the island is often mistaken as "Dolphin Island"; dauphin is "dolphin" in the French language.
The Gulf of Mexico is to the south of the island; the Mississippi Sound and Mobile Bay are to the north. The island's eastern end helps define the mouth of Mobile Bay. The eastern, wider portion of the island is shaded by thick stands of pine trees and saw palmettos, but the narrow, western part of the island features scrub growth and few trees.
Dauphin Island is home to Fort Gaines, Dauphin Island Sea Lab, The Estuarium public aquarium, the Dauphin Island Airport, boat ramps, a large public pier (that sits on dry land), historic sites, several restaurants, new condominium developments, and numerous private homes. Beaches attract tourism, and fishing is a popular activity in the waters around the island. The island is connected to the mainland by the Gordon Persons Bridge.
Although the island has several bird sanctuaries, the main one is the 164-acre (66 ha) Audubon Bird Sanctuary. Dauphin Island is the first landfall encountered by many birds as they migrate north from South America, and as a consequence many species can be found resting there before continuing their journey.
In May 2012, the central public beach began charging for access. This marked the second beach on the island to charge the public following the creation of the privately owned West End Beach.