Spetses (Greek: Σπέτσες, Ancient Greek: Πιτυοῦσσα "Pityussa") is an island in Attica, Greece. It is counted among the Saronic Islands group. Until 1948, it was part of the Argolis and Corinthia Prefecture, which is now split into Argolis and Corinthia. In ancient times, it was known as Pityussa.
The island is now an independent municipality, with no internal boundaries within the municipality. The town of Spetses is the only large settlement on the island. The other settlements on the island are Moní Ayíon Pánton, Ligonéri, Ágioi Anárgyroi, Kouzoúnos. Also part of the Municipality of Spetses are the islands of Spetsopoula, Falkonera, and Velopoula (all uninhabited). The municipality has an area of 27.121 km.