Polyaigos is an uninhabited Greek island in the Cyclades near Milos and Kimolos. It is part of the community of Kimolos.
Its goat population maintains Polyaigos as a barren island. It has, however, some magnificent beaches, mainly on the southern part of the island, as well as many sea-surface caves, which serve as a refuge to a dwindling population of mediterranean monk seals (monachus-monachus).
There are two mountains in Polyaigos island, Stroggylo which rises to 330 metres and Psilo Vouno at 370 meters.
The island is to a great extent privately owned by the Greek Orthodox church, which sublets parts of it to local herdsmen from the nearby islands of Milos and Kimolos.