An optical transceiver has: an optical subassembly (OSA) having a built-in optical element and a cylindrical receptacle to conduct an optical path from the optical element; a chassis having an entrance that allows insertion of an optical fiber to be connected to the optical path; an OSA holder engaged with the receptacle to hold the OSA and accommodated in contact with an inside portion of the chassis; and an OSA holder-regulating portion formed in the chassis to regulate the OSA holder, the OSA holder-regulating portion being positioned opposite the entrance relative to the OSA holder.