Skiathos is a city and a small island in the Aegean Sea belonging to Greece. It is next to Skopelos and consists of a main town (Skiathos Town) and the communities of Koukounaries, Kanapitsa, Vromolimnos and Troullos. Skiathos is the westernmost island in the Sporades group of islands. The mainland of Greece along with Magnesia is to the west. The island of Skiathos has 70 beaches all around it. Skiathos covers 58 square kilometres, being about 12 kilometres from east to west and six kilometres at its widest point. Irregular in shape, it is largely mountainous with a maximum elevation of 433 metres.

Skiathos Town is a port which shelters small boats and from where ferry services connect to Skopelos, Volos, Agios Konstantinos and the rest of Greece.

Greek mythology says that when the Greek gods had finished building their palace on Mount Olympus, some stones were left over. Then Zeus took those stones and cast them down to the Aegean sea. As a result Skiathos and the Northern Sporades Islands came to be.