Saltes Island (Spanish: Isla Saltés) is a small fluvial island located in the Huelva River estuary in the province of Huelva, Andalusia, Spain. The island is part of the Odiel Marshes biosphere reserve.
Saltes Island is the southernmost island within the Odiel Marshes Natural Park, the second largest wetland in Andalusia. It lies at the confluence of the Odiel and Rio Tinto rivers. The island is mostly swamp with sand-covered ridges up to 3 metres (9.8 ft) high. Its soil hosts an important ecosystem of flora and fauna, including species of spoonbills, flamingos, egrets and storks.
Saltes Island and the nearby city of Huelva are possible sites of the semi-mythical city of Tartessos. In his Ora Maritima, the Roman poet Avienus referred to Tartessos as the "island between two rivers." Previously, the Greek historian Strabo wrote of Phoenicians sailing to the area in the 8th century BC whose oracle told them to build a temple for Hercules. Historically, between the legend and Biblical references to Tarshish in the Book of Kings, Tartessos had come under Greek influence in the mid-seventh century BC.