A planar illumination apparatus according to an embodiment includes a light guide plate that includes an emission surface that emits light and a reflective surface that is a surface opposite to the emission surface and that reflects light, a light blocking member that defines an effective region of the emission surface, and a light source arranged so as to face a light incident side surface of the light guide plate. In a portion of the effective region beside a light blocking region of the light blocking member, a first reflective surface is provided that includes a region that is inclined in a direction approaching the emission surface side with an increase in a distance from the light incident side surface.