A light diffusion sheet for overlaying is to be provided on a front face side of a prism sheet in a backlight unit of a liquid crystal display device, and has a substrate layer and a light diffusion layer overlaid on a front face side of the substrate layer, in which the light diffusion layer contains a resin matrix and resin beads dispersed in the resin matrix, wherein: a mode diameter in a volume-weighted particle size distribution of the resin beads is no less than 2.5 μm and no greater than 5.5 μm; a density of the resin beads per unit area is no less than 9,000 beads/mm2 and no greater than 24,000 beads/mm2; and an average thickness of the light diffusion layer is no less than 2 μm and no greater than 9 μm.