Konstantinos Mazarakis-Ainian (Greek: Κωνσταντίνος Μαζαράκης-Αινιάν, c. 1869–1949) was a Hellenic Army officer who rose to the rank of Lieutenant General.

He fought in the Greco-Turkish War of 1897, and led a guerrilla band during the Macedonian Struggle under the nom de guerre of Kapetan Akritas (Καπετάν Ακρίτας).

In the Balkan Wars, he led volunteer scout detachments; his units operated in advance and in the flanks of the main army, and played a crucial role in the capture of vital bridges and railways.

He returned to Greece in 1919 to assume command of the Xanthi Division during the occupation of Western Thrace.

In 1920, he led his division to a landing on Bandirma during the Greek offensive against the Kemalists, and shortly after in the occupation of Eastern Thrace, against the local Turkish forces of Cafer Tayyar.