A display device includes a timing controller which supplies a clock training signal through a data clock signal line and a first control signal through a shared signal line in a first period of one frame, and supplies image data through the data clock signal line in a second period of the one frame, a data driver provided with data driving circuits which generate a clock signal based on the clock training signal and the first control signal in the first period, and generate data voltages based on the clock signal and the image data in the second period, and a pixel part which receives the data voltages from the data driver. The data driver may supply a second control signal indicating a reception state of the data driver to the timing controller through the shared signal line in the second period.