A backlight unit has a light source, a reflection sheet, a light guide plate, an air space, and a diffuser, wherein the reflection sheet, the light guide plate, the air space, and the diffuser are overlaid in this order. The light source is configured to arrange individual light sources having different spectra or different light emission quantities near an incident plane of the light guide plate, and on a plane facing the reflection sheet of the light guide plate, scatter dots are disposed which take light propagating through the light guide plate out of the reflection sheet side. The backlight unit and a liquid crystal display device including the same have excellent display quality.