Demasq Kaja (died August 25, 1327) was a member of the Chobanid family during the middle of the fourteenth century. He was the son of Coban. During the 1320s, Coban accumulated a great deal of power as an amir of the Ilkhanate. While technically serving the Ilkhan Abu Sa'id, he was the effective power behind the throne. He therefore divided up Persia between himself and his sons. Demasq became viceroy of Azerbaijan and Iraq. In addition, he gained the use of the powers that the vizier Rukn al-Din Sa'in had been invested with.