A display device includes a window, a polarizing layer disposed directly on a lower portion of the window or attached to the lower portion of the window by an adhesive layer having a thickness smaller than about 5 micrometers, a retard layer disposed under the polarizing layer, and a display panel disposed under the polarizing layer. The retard layer includes a first retard layer and a second retard layer. At least one selected from a functional layer and a support plate is further disposed under the display panel. The functional layer includes at least one selected from a cushion layer and a digitizer, and the functional layer has a step difference.