It is administratively part of the municipality of Alonnisos in the Sporades regional unit.

In Antiquity it was known as Ephthyros (Έφθυρος) and Polyaigos (Πολύαιγος)[citation needed].

A bay in the southwest of the island is named Agios Petros.

Kyra Panagia has belonged to the Athonite monastery of Megisti Lavra, located on Mount Athos, since it was granted the island by the Byzantine emperor Nikephoros II Phokas in 963.

There is a monastery renovated in 2017 after 8 years of work and inhabited by a single monk, on the east coast of the island.