A backlight unit for a display device includes: a light guide including a light incident surface; a substrate facing the light incident surface; a plurality of light sources on one surface of the substrate facing the light incident surface; and a first member disposed between the substrate and the light incident surface to space the light sources apart from the light guide. The first member includes: a support on one surface of the substrate that do not include the light source, the support having a first surface facing the light incident surface and a second surface facing the light sources; and a first layer disposed on the first surface and the second surface of the support to improve luminance uniformity across the light incident surface.