Konstantinos Kallaris (Greek: Κωνσταντίνος Καλλάρης, 1858–1940) was a senior Hellenic Army officer who distinguished himself in the Balkan Wars of 1912–1913. Born in Athens in 1858, Kallaris studied at the Hellenic Military Academy and was commissioned into the Army on 28 July 1880 as an Ensign of Engineers. He fought in the Greco-Turkish War of 1897. Due to his extensive education, he was placed in the General Staff Corps upon its creation in 1905. In early 1911 he was placed as commander of the 2nd Infantry Division at Athens, which quickly became a model formation under the supervision of the French military mission to Greece.