sheltered bay of the Atlantic Ocean, eastern coast of Brazil. A natural harbour, it is 25 miles (40 km) long and 20 miles (32 km) wide. Salvador, the principal seaport and capital of Bahia state, is on the peninsula that separates the bay from the Atlantic. Todos os Santos Bay receives the Paraguaçu River and is surrounded by the Recôncavo, a fertile coastal lowland. Its main channel is dredged from the Atlantic entrance to the port of São Francisco do Conde, an outlet for the petroleum refinery at Mataripe. Brazil's first producing oil field is on the bay's northeast shore between Candeias and Lobato.

Early in the 18th century, many African slaves were shipped to the bay region to work sugar plantations. The bay was named by its discoverer Amerigo Vespucci, the Italian navigator, who is said to have entered it on All Saints' Day, Nov. 1, 1501.