According to one embodiment, an illumination device includes a light source module including a plurality of light sources, and a reflector opposed to the light source module. The reflector includes a plurality of incidence openings on which light from the light sources is made incident, a plurality of emission openings opposed to the incidence openings, and a plurality of reflective surfaces extending from the incidence openings to the emission openings, respectively. Each of the reflective surfaces is formed by combining a plurality of curved surfaces arranged in an optical axis direction of the light sources.