According to one embodiment, a display device includes a display panel including a first sub-display area and a second sub-display area and an illumination device which illuminates the display panel, the illumination device including a first light guide opposing the first sub-display area, a second light guide opposing the second sub-display area, and a light diffusion layer disposed between the display panel and each of the first light guide and the second light guide, the light diffusion layer exhibiting a first diffusion degree in a first direction along which the first light guide and the second light guide are arranged, which is higher than a second diffusion degree in a second direction crossing the first direction.