Spetses is an island and a municipality in the Islands regional unit, Attica, Greece. It is sometimes included as one of the Saronic Islands. Until 1948, it was part of the old prefecture of Argolidocorinthia, which is now split into Argolis and Corinthia. In ancient times, it was known as Pityoussa, and later as Petses. The town of Spetses is the only large settlement on the island.