There is provided a fixing device including: a heating member that, while rotating, heats and fixes a developer image onto a recording medium; a pressing member that nips and presses the recording medium between itself and the heating member; an external heating member configured to make contact with an outer surface of the heating member and to move away from the outer surface of the heating member, the external heating member making contact with the outer surface of the heating member and heating the heating member; and a moving section that computes a contact position of a leading edge of the recording medium and the outer surface of the heating member, and moves the external heating member such that the external heating member contacts the outer surface of the heating member based on the computed position.