Kyra Panagia or Pelagos is an uninhabited Greek island in the Aegean Sea, part of the Northern Sporades chain. The 1991 census read only one inhabitant making it the smallest municipal district in Greece in population. The tiny settlement became abandoned in the mid to late-1990s and now has nothing.
It belongs to the Alonisssos Municipality.
In ancient times, the island was known as Euthyra. It is called Kyra-Panagia after a monastery built on the eastern side of the island by monks from Athos in Byzantine times.
The island is also known by the name of Pelagos and rarely Pelagonissi, it was known as Ephthyros (Modern Greek form: Efthiros or Efthyros) and Polyaigos. The bay near the island is named Agios Petros.
The island lies within the National Marine Park of Alonissos.