Provided are a backlight assembly and a display device including the same.The backlight assembly comprises: a housing; a plurality of light sources disposed on the housing; a plurality of optical lenses disposed on the light sources, respectively; a main reflective sheet covering an upper surface of the housing and comprising a reflective portion and a main opening which exposes each of the optical lenses; and a sub reflective sheet disposed under each of the optical lenses, wherein the sub reflective sheet comprises a body portion and a fitting portion partially separated from the body portion and is fitted to the main reflective sheet in the reflective portion.