Konstantinos G. Karamanlis (Greek: Κωνσταντίνος Γ. Καραμανλής, pronounced [konstaˈdinos karamanˈlis]; 8 March 1907 – 23 April 1998), commonly anglicised to Constantine Karamanlis or just Caramanlis, was a four-time Prime Minister and twice President of the Third Hellenic Republic, and a towering figure of Greek politics, whose political career spanned much of the latter half of the 20th century.The longest serving Prime Minister of modern Greek history (c. 14 years), during his first term (1955-1963) he applied a program of rapid industrialization, heavy investment on infrastructure and improvement on agricultural production, which led to the post-war Greek economic miracle. He implemented also the extension of full voting rights to women, which stood dormant since 1952.

In his second term, after 1974, he is recognised for his successful restoration of Democracy after the Greek military junta and by establishing the Third Hellenic Republic, bringing an end to continuous military coups and the political instability of around half a century.

A devoted pro-Europeanist, he is credited also for the country's accession to the European Communities. In 1978 he was awarded the Charlemagne Prize.

His supporters lauded him as the charismatic Ethnarches (National Leader).