There are provided an illumination unit capable of reducing formation of a double image in three-dimensional display and a display unit including the same. An illumination optical system configured to generate linear illumination light formed by two-dimensionally arranging a plurality of linear illumination light beams or a plurality of point-like illumination light beams, and a reflective plate configured to reflect the linear illumination light are included. The reflective plate reflects the linear illumination light to or close to a plane passing through a part that generates the linear illumination light and being perpendicular to a plane including the reflective plate.