The area of the island is 477.395 km2 and it is 43 km long and 13 km wide. It is separated from Anatolia by the approximately 1-mile-wide (1.6 km) Mycale Strait.
While largely mountainous, Samos has several relatively large and fertile plains. A great portion of the island is covered with vineyards, from which muscat wine is made. The most important cities except the capital, Vathy, in the northeast, are that of Karlovasi, in the northwest, Pythagoreio, in the southeast, and Marathokampos in the southwest.