There is provided an optical body and a display device that enable wavelength dependence of a reflectance to be reduced and reflection of incident light to be further suppressed, the optical body including: a concave-convex structure formed on a surface of a base material. An average period of concavities and convexities of the concave-convex structure is equal to or shorter than a wavelength belonging to a visible light band. A standard deviation of differences between respective positions of bottom faces of the concavities of the concave-convex structure in a normal direction of a flat surface of the base material and a median of the positions of the bottom faces is greater than or equal to 25 nm.