Sifnos is located in the Aegean Sea and it belongs to the south-western Cyclades (located between Serifos, Kimolos and Paro

Sifnos is a medium-sized island; it has an area of 73, 2 km² and a shoreline of 73 km. To the south of Sifnos, there is the small islet of Kitriani.

Sifnos is traversed by four parallel mountain chains and its main summits are those of Prophitis Ilias (682 m.), at the center of the island and of Agios Simeon (463 m.) in the North.

According to the last population census (2011) the permanent residents of the island are 2.570.

Sifnos' soil consists of rocks of granite, loamy sandstone or schist, limestone and of minerals such as iron, copper, zinc, manganese, galena, magnesium etc. In the ancient times, Sifnos had gold and silver mines and quarries of “Sifnian Stone”, from which the Sifnians were creating the famous tableware such as the “sifnian glasses”.

The island is connected to Piraeus, Milos, Kimolos, Serifos, Kythnos, Paros and Syros by boat all year round. Boat traffic increases during the summer months and more connections are added. At the area of Tholos in the South-east, there is a heliport. The closest airports to the island are those of Paros, of Milos and of Syros.