A backlight includes light emitting diodes; a substrate on which light emitting diodes are mounted; and a reflection sheet. The surface on which the light emitting diodes are mounted of the substrate is opposed to a rear surface of the liquid crystal display panel. The liquid crystal display panel and the substrate each have a shape in which a common width in a first direction is longer than a width in a second direction, which is orthogonal to the first direction. The width of the substrate in the second direction is shorter than the width of the liquid crystal display panel in the second direction. The substrate is opposed to, while avoiding being opposed to both end portions of the liquid crystal display panel in the second direction, a central portion between the both end portions of the liquid crystal display panel.