A fixing device incorporated in an image forming apparatus and for fixing a toner image on recording paper includes a fixing roller in which a heater is installed in the roller, a pressure roller which is held in press contact with the fixing roller, an oil application roller which is held in contact with the fixing roller for applying oil to the fixing roller, an oil supply roller which is held in contact with the oil application roller for applying oil to the oil application roller, an oil application felt which is held in contact with the oil supply roller for applying oil to the oil supply roller, and a driver which rotates the oil application roller such that the oil application roller moves in the same direction as the fixing roller at the contact portion between the fixing roller and the oil application roller. The surface velocity of the oil application roller is lower than the surface velocity of the fixing roller.