Konstantinos Tsaldaris (Greek: Κωνσταντίνος Τσαλδάρης, 14 April 1884 – 15 November 1970) was a Greek politician and twice Prime Minister of Greece. Tsaldaris was born in Alexandria, Egypt. He studied law at the University of Athens as well as Berlin, London and Florence. He became a prefectural politician from 1915 to 1917.