A planar illumination apparatus according to an embodiment includes: a frame including a bottom surface that is curved as viewed in a cross section, and a side wall that is provided in a standing manner so as to surround a circumference of the bottom surface; a light guide plate that is housed in the frame, that is curved along the bottom surface as viewed in the cross section, and that includes an emission surface for emitting light; and a plurality of optical sheets that are arranged along the emission surface of the light guide plate and that overlap with one another in a plan view. An end portion of at least one of the plurality of optical sheets is fixed to an upper end surface of the side wall of the frame via a fixing member.