According to an aspect of the invention, an optical receptacle, comprising: a fiber stub including an optical fiber, a ferrule, and an elastic member, the optical fiber including cladding and a core conducting light, the ferrule having a through-hole fixing the optical fiber, the elastic member fixing the optical fiber in the ferrule; and a holder holding the fiber stub, the optical fiber being disposed inside the through-hole over an entire region of the optical fiber, the optical fiber including a portion, a core diameter and a fiber outer diameter in the portion decreasing gradually toward an end surface of the ferrule on a side opposite to a side to be optically connected to a plug ferrule, the elastic member being filled into a space between the optical fiber and an inner wall of the through-hole. By making the core small at the optical element side end surface of the optical fiber while contributing to shortening the optical module total length, the strength of the deformable portion of the optical fiber can be ensured; the occurrence of breaking and cracks can be prevented; and the decrease of the coupling efficiency can be prevented by suppressing the movement of the optical fiber when using the optical module.