Samos (, also US: ; Greek: Σάμος [ˈsamos]) is a Greek island in the eastern Aegean Sea, south of Chios, north of Patmos and the Dodecanese, and off the coast of western Turkey, from which it is separated by the 1.6-kilometre (1.0 mi)-wide Mycale Strait. It is also a separate regional unit of the North Aegean region.

In ancient times, Samos was an especially rich and powerful city-state, particularly known for its vineyards and wine production. It is home to Pythagoreion and the Heraion of Samos, a UNESCO World Heritage Site that includes the Eupalinian aqueduct, a marvel of ancient engineering. Samos is the birthplace of the Greek philosopher and mathematician Pythagoras, after whom the Pythagorean theorem is named, the philosophers Melissus of Samos and Epicurus, and the astronomer Aristarchus of Samos, the first known individual to propose that the Earth revolves around the sun. Samian wine was well known in antiquity and is still produced on the island.

The island was governed by the semi-autonomous Principality of Samos under Ottoman suzerainty from 1835 until it joined Greece in March 1913.