A display device includes a display panel including gate lines, data lines, and pixels connected to the gate lines and the data lines and a driving circuit which controls the display panel in response to an image signal, a control signal, and a mode signal from an outside to display an image through the display panel. The driving circuit converts the image signal to data voltage signals corresponding to a first gamma curve to apply the data voltage signals to the data lines when the mode signal represents a normal mode and converts the image signal to data voltage signals corresponding to a second gamma curve different from the first gamma curve to apply the data voltage signals to the data lines when the mode signal represents a frequency variable mode.