Constantine Gabras or Gavras (Greek: Κωνσταντίνος Γαβρᾶς) was the governor or doux (duke) of the Byzantine province of Chaldia, centred on the Black Sea port of Trebizond and its mountainous hinterland, the Pontic Alps, in northeast Anatolia, now part of Turkey. Gabras ruled Chaldia as a semi-independent prince between 1126 and 1140.