An optical-diffusion film for display which, particularly when applied to a display device using a collimated backlight as a backlight for the display panel, can efficiently diffuse and emit a highly directional light emitted from the collimated backlight toward the front of the display device as image display light, without allowing straight transmission of the highly directional light, and a display device using the optical-diffusion film for display are provided.Disclosed is a single layered optical-diffusion film having a columnar structure in which plural pillar-shaped objects having a relatively high refractive index are arranged to stand close together in a film thickness direction in a region having a relatively low refractive index, in which the film thickness of the optical-diffusion film has a value within the range of 60 to 700 μm, and the haze value obtainable in the case in which light is made incident in the normal line direction of the film plane has a value of 80% or more.