Adamantios Korais or Koraïs (Greek: Ἀδαμάντιος Κοραῆς [aðaˈmandi.os koraˈis]; Latin: Adamantius Coraes; French: Adamance Coray; 27 April 1748 – 6 April 1833) was a Greek scholar credited with laying the foundations of Modern Greek literature and a major figure in the Greek Enlightenment. His activities paved the way for the Greek War of Independence and the emergence of a purified form of the Greek language, known as Katharevousa. Encyclopædia Britannica asserts that "his influence on the modern Greek language and culture has been compared to that of Dante on Italian and Martin Luther on German".

Korais was born in Smyrna, in 1748. His father Ioannis, of Chian descent, was demogérontas in Smyrna; a seat similar to the prokritoi of mainland Greece, but elected by the Greek community of the town and not imposed by the Ottomans.

He was exceptionally passionate about philosophy, literacy and linguistics and studied greatly throughout his youth. He initially studied in his home place, where he graduated from the Evangelical Greek School.

After his school years, he lived for a while in Amsterdam as a merchant, but soon he decided that he wanted to study in a university. He studied also the Jewish, Dutch, French and English languages, apart from his knowledge of ancient Greek and Latin.

Korais studied at the school of medicine of the University of Montpellier from 1782 to 1787. His 1786 diploma thesis was entitled Pyretologiae Synopsis, while his 1787 doctoral thesis was entitled Medicus Hippocraticus.

He traveled to Paris where he would continue his enthusiasm for knowledge. There he decided to translate ancient Greek authors and produced thirty volumes of those translations, being one of the first modern Greek philologists and publishers of ancient Greek literature.

After 1788 he was to spend most of his life as an expatriate in Paris. As classical scholar, Korais was repelled by the Byzantine influence on Greek society and was a fierce critic of the lack of education amongst the clergy and their subservience to the Ottoman Empire, although he conceded it was the Orthodox Church that preserved the national identity of Greeks.

Korais believed Western Europe was the heir of the ancient Greek civilization, which had to be transmitted to the modern Greeks through education. Additionally, he advocated the restoration and use of the term "Hellene" (Έλληνας) or "Graikos" (Γραικός) as an ethnonym for the Greeks, in the place of Romiós, that was seen negatively by him.

While in Paris, he was witness to the French Revolution. He was influenced by the revolutionary and liberal sentiments of his age. He admired Thomas Jefferson; and exchanged political and philosophical thoughts with the American statesman. A typical man of the Enlightenment, Korais encouraged wealthy Greeks to open new libraries and schools throughout Greece. Korais believed that education would ensure not only the achievement of independence but also the establishment of a proper constitution for the new liberated Greek state. He envisioned a democratic Greece, recapturing the glory of the Golden Age of Pericles.

Korais died in Paris aged 84 soon after publishing the first volume of his autobiography. In 1877, his remains were sent to Greece, to be buried there.