A diffusion sheet diffuses light to enhance luminance uniformity. The diffusion sheet includes a base film and a diffusion layer. The base film is optically transparent. The diffusion layer is formed on a surface of the base film. The diffusion layer includes a diffusion pattern having a plurality of first diffusion members that enhance front-view luminance. A cross-section of each of the first diffusion members having an arch shape, the cross-section being taken along a line that is substantially perpendicular to a longitudinal direction of the first diffusion members. The backlight assembly requires no prism sheet, which is usually used for enhancing front-view luminance, thus lowering the manufacturing cost.