A display device includes a display unit which includes pixels and gate lines and data lines connected to the pixels, a data driver connected to the data lines, and a signal controller which outputs a first frequency data control signal to the data driver at a predetermined frame frequency and outputs a second frequency data control signal to the data driver in synchronization with a vertical synchronization signal received from a graphics processing unit, wherein the data driver outputs a first data voltage to the data lines in accordance with the first frequency data control signal, and stops the output of the first data voltage and outputs a second data voltage to the data lines when the second frequency data control signal is inputted while outputting the first data voltage to the data lines.