Greek (Ελληνικά IPA: [eliniˈka] or Ελληνική γλώσσα, IPA: [eliniˈci ˈɣlosa]) is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history; other systems, such as Linear B and the Cypriot syllabary, were previously used. The alphabet arose from the Phoenician script, and was in turn the basis of the Latin, Cyrillic, Coptic, and many other writing systems.

The Greek language holds an important place in the histories of Europe, the more loosely defined "Western" world, and Christianity; the canon of ancient Greek literature includes works of monumental importance and influence for the future Western canon, such as the epic poems Iliad and Odyssey. Greek was also the language in which many of the foundational texts of Western philosophy, such as the Platonic dialogues and the works of Aristotle, were composed; The New Testament of the Christian Bible was written in Koiné Greek and the liturgy continues to be celebrated in the language in various Christian denominations (particularly the Eastern Orthodox and the Greek Rite of the Catholic Church). Together with the Latin texts and traditions of the Roman world (which was significantly influenced by ancient Greek society), the study of the Greek texts and society of antiquity constitutes the discipline of Classics.