An optical transmission apparatus includes an optical element that has at least one of a light emitting part and a light receiving part on a surface opposed to a mounting surface of the optical element, an optical waveguide that is made of a polymer material, and has an optical path deflecting part in a through hole or an opening, wherein the optical path deflecting part deflects an optical path of the optical with respect to the at least one of the light emitting part and the light receiving part of the optical element, and a substrate that has a mounting region on which the mounting surface of the optical element is mounted, and a plurality of waveguide holding parts, each holding the optical waveguide so that the optical path deflecting part of the optical waveguide is arranged opposite to the at least one of the light emitting part and the light receiving part of the optical element.