Andros is the northernmost island of the Greek Cyclades archipelago, about 10 km (6 mi) southeast of Euboea, and about 3 km (2 mi) north of Tinos. It is nearly 40 km (25 mi) long, and its greatest breadth is 16 km (10 mi). It is for the most part mountainous, with many fruitful and well-watered valleys. The municipality, which includes the island Andros and several small, uninhabited islands, has an area of 380 km2 (146.719 sq mi). The largest towns are Andros (town), Gavrio, Batsi, and Ormos Korthiou.

The Cyclades are an island group in the Aegean Sea, southeast of mainland Greece and a former administrative prefecture of Greece. They are one of the island groups which constitute the Aegean archipelago. The name refers to the archipelago forming a circle around the sacred island of Delos. The largest island of the Cyclades is Naxos, however the most populated is Syros.