According to one embodiment, a display device includes a display panel, a first wiring board mounted on the display panel, and a backlight unit located on a back surface side of the display panel to illuminate the display panel. The backlight unit includes a casing which includes a bottom plate including a first slit and a side plate standing at the bottom plate, and a light guide arranged in the casing. The first wiring board passes between the side plate and the light guide and through the first slit and is bent toward a back surface side of the casing.