A light diffusing plate is formed of a birefringent film containing dispersed therein minute regions differing from the birefringent film in birefringent characteristics. The minute regions are formed of a thermoplastic liquid-crystal polymer. The difference in refractive index between the birefringent film and the minute regions in a direction perpendicular to the axis direction in which a linearly polarized light has a maximum transmittance, Δn1, is 0.03 or larger and that in said axis direction, Δn2, is not larger than 80% of the Δn1. An optical element is formed of a multilayer structure of the above light diffusing plate and at least either of a polarizing plate and a phase plate. A liquid-crystal display is formed of a liquid-crystal cell and, disposed on one or each side thereof, either the above light diffusing plate or the above optical element.