A touch display device includes: a first substrate, a plurality of gate lines and a plurality of data lines on the first substrate, and crossing each other to define a plurality of pixel regions, a plurality of thin film transistors connected to respective ones of the plurality of gate lines and the plurality of data lines, the plurality of thin film transistors being in respective ones of the plurality of pixel regions, and a plurality of bar-shaped sensing electrodes crossing the gate lines, wherein, to determine whether a touch is performed, the touch display device is configured such that: gate signals are transmitted to the plurality of gate lines, a direct current (DC) voltage is applied to the plurality of bar-shaped sensing electrodes, and a change in ripple component of the DC voltage applied to the bar-shaped sensing electrodes is received.