A method and apparatus for generating gradation voltages are provided. Maximum and minimum reference voltages are selected from a distribution of voltages ranging from a first source voltage to a second source voltage. The maximum reference voltage is selected as a 1st gradation voltage and the minimum reference voltage is selected as an Nth gradation voltage, or vice versa, in response to an inversion control signal, where N is a natural number. First to Mth gamma voltages are selected from among a plurality of voltages generated by a voltage distribution between the 1st gradation voltage and the Nth gradation voltage. Second to (N−1)th gradation voltages are generated from a voltage distribution between the 1st gradation voltage and the Nth gradation voltage, using the 1st gamma voltage to the Mth gamma voltage, where M is a natural number.