According to one embodiment, a display device includes a display panel and an illumination device. The illumination device includes a light source unit, at least one light-shielding body which blocks part of the light emitted from the light source unit, at least one lens which refracts the light emitted from the light source unit, and an illumination controller. The illumination controller controls a first mode in which the light-shielding body and the lens are arranged at a first position, and a second mode in which at least one of the light-shielding body and the lens is arranged at a second position, which is different from the first position.