According to one embodiment, a display device includes a liquid crystal display panel and a backlight device. The backlight device includes a light guide plate opposed to the back surface of the liquid crystal display panel, and light sources opposed to a light incident surface of the light guide plate. The light guide plate includes divided light guide plates, each having a first main surface, a second main surface, the light incident surface, and side surfaces cross to the main surface and the light incident surface, and an adhesive member connecting the side surfaces of the divided light guide plates to each other and having optical properties different from optical properties of the divided light guide plates.