A display device including: a timing controller configured to supply an adjustment option value through a data clock signal line during a first initialization period, and generate second data based on first data and a control signal and supply the second data through the data clock signal line during a data period; a data driver configured to generate an adjustment value based on the adjustment option value during the first initialization period, and generate third data based on the adjustment value and the second data and generate a data signal based on the third data during the data period; and a pixel configured to display an image based on the data signal.