Provided is a super twist nematic (STN) liquid crystal display (LCD) driver which reduces power consumption. The STN LCD driver includes a reference voltage generating unit, a voltage boosting unit, a voltage control unit, a first common voltage generating unit, and a second common voltage generating unit. The reference voltage generating unit generates a reference voltage in response to an external voltage. The voltage boosting unit generates a boosting voltage by boosting the external voltage. The voltage control unit generates a first segment voltage and a second segment voltage which drive a segment electrode of the STN LCD panel in response to the reference voltage and the boosting voltage. The first common voltage generating unit drives a common voltage of the STN LCD panel in response to the external voltage, a ground voltage, and the first segment voltage and generates a first common voltage, the voltage level of which is higher than the voltage level of the first segment voltage, using a predetermined resistance ratio. The second common voltage generating unit drives a common voltage STN LCD panel in response to the external voltage, the ground voltage, and the first segment voltage and generates a second common voltage, the voltage level of which is lower than the voltage level of the first segment voltage, using a predetermined resistance ratio.