Provided are a display device and a driving method thereof. The display device includes a display panel including a plurality of pixels defined by allowing a plurality of gate lines and a plurality of data lines to intersect each other; a timing controller generating a gate control signal, a data control signal, a MUX clock signal, and image data; a gate driving circuit sequentially providing gate signals to the plurality of gate lines based on the gate control signal; a data driving circuit supplying a data signal to the plurality of data lines based on the image data and the data control signal to drive the pixels; and a MUX circuit receiving the data signal and outputting the data signal in a time division manner to the data lines according to the MUX clock signal. The timing controller includes a slew rate control unit controlling a slew rate of the MUX clock signal.