The word 'Greeks' derives from the Latin 'Graeci'used by the Romans.

According to a theory, Graikhos (singular) is the "inhabitant of Graia" (lit. "gray"), a town on the coast of Boeotia, which was the name given by the Romans to all Greeks, originally to the Greek colonists from Graia who helped found Cumae (9th century BCE), the important city in southern Italy where the Latins first encountered Greeks.

Ancient Greeks mostly thought of themselves in terms of more localized ethnic and political groupings: the Athenians, the Spartans, the Dorians, and so forth. The term "Hellenes" as a collective name for all Greeks started to become popular during the 4th century BCE. Originally the Hellenes were a Thessalian tribe, first mentioned by Homer.