It is to provide an optical element, an optical module holder including the optical element, an optical module, and an optical connector that can attenuate with high accuracy an amount of light coupled between an optical transmission line and a photonic element using light refraction, thereby realizing appropriate optical communication while reducing manufacturing costs.A light attenuating refractive surface 7 is formed on an optical surface 4 disposed on an optical path between an optical transmission line 2 and a photonic element 3 in a main body of the optical element. The light attenuating refractive surface 7 attenuates the amount of light coupled between the optical transmission line 2 and the photonic element 3 by refracting and deflecting incident light.