A backlight unit and a display device including the same are disclosed. The backlight unit includes a frame including a bottom area and a sidewall area extended from the bottom area, at least one substrate positioned at a front surface of the frame, a plurality of light sources being mounted on the at least one substrate, a reflective sheet positioned at a front surface of the at least one substrate, and an optical sheet positioned at a front surface of the reflective sheet. The reflective sheet includes a first sheet area contacting the bottom area and including a plurality of lens holes, and a second sheet area spaced apart from the bottom area and including a dot area. The dot area includes a first dot area and a second dot area spaced apart from the first dot area.