A backlight apparatus includes a light source emitting blue light, a light guide layer, a quantum dot phosphor layer, a reflective layer, and a yellow phosphor layer. The light guide layer includes a first main surface, a second main surface, at least one light-receiving side surface, and at least one non-light-receiving side surface. The quantum dot phosphor layer is provided on the first main surface side of the light guide layer and includes a red quantum dot phosphor and a green quantum dot phosphor. The reflective layer is disposed on the second main surface side of the light guide layer. The yellow phosphor layer is provided between the second main surface and the reflective layer and in a region along the at least one non-light-receiving side surface, and includes a yellow phosphor. The quantum dot phosphor layer is in contact with the first main surface.