A display device includes: a display panel in which a plurality of data lines and a plurality of gate lines intersect in a matrix form and pixels are formed at intersecting points thereof; a data drive unit connected to the plurality of data lines and configured to output a black data voltage corresponding to a gradation level of 0 and expressing the black data voltage as a third voltage through the data lines, the third voltage greater than a first voltage, which is a minimum output value, and less than or equal to a second voltage corresponding to a gradation level of 0 when linearly extending data voltages of two or more low gradation levels; a gamma voltage supply unit outputting a gamma voltage for each gradation level to the data drive unit; and a timing controller generating a control signal to control driving of the display panel.