According to one embodiment, a display device includes a first transparent substrate, a second transparent substrate, a liquid crystal layer, light-emitting elements disposed in a first direction, a third transparent substrate including a main surface and a side surface opposed to the light-emitting elements, and a transparent layer disposed on the main surface and having a lower refractive index than the third transparent substrate. The third transparent substrate is bonded to the first transparent substrate or the second transparent substrate with the transparent layer sandwiched in between. The transparent layer includes strip portions disposed in the first direction and extended along a second direction.