A display device and a driving method thereof are disclosed. The display device includes a display panel including a plurality of pixels connected to data lines; a data driver connected to the data lines and configured to determine first data voltages corresponding to the pixels, to generate second data voltages by adding a compensation voltage to the first data voltages, and to supply the second data voltages to the pixels through the data lines; and a crosstalk compensator connected to the data driver and configured to calculate the compensation voltage by comparing the first data voltages corresponding to pixels disposed in at least three adjacent horizontal lines.