Provided are a display device and a data driver. The disp lay device comprises a display panel in which a plurality of data lines and a plurality of gate lines are disposed and a plurality of subpixels are arrayed; a data driver supplying a video data signal including a first signal segment and a second signal segment maintaining a predetermined voltage difference to each of the plurality of data lines and outputting readout data in response to signal sensing through each of the plurality of data lines to which the video data signal is supplied; and a touch controller detecting a touch or determining touch coordinates in accordance with the readout data. In the present invention, both display driving and touch sensing are performed without a dedicated touch sensor structure. It is possible to simultaneously perform the display driving and the touch sensing.