The currency in Senegal is the West African CFA franc (currency code XOF) and it has an official fixed exchange rate to the euro: 1 Euro= 655 CFA (although the commonly accepted 'street exchange rate' is 1 Euro= 650 CFA). You can exchange Euros on the island or on the mainland. There are no ATMs on the island, but you can find plenty on the mainland and at the airport.