A display device includes a display panel, a back light unit configured to provide light to the display panel, and a guide panel covering side surfaces of the display panel and the back light unit. The guide panel includes a dual partition wall structure of an inner partition wall and an outer partition wall, a first extension that is extending from and integral with the dual partition wall structure, and a second extension protruding in a direction perpendicular to the dual partition wall structure to be between the back light unit and the display panel.