An optical receptacle comprises: a first optical surface; a first transmission part; a light separation unit; and a third optical surface. The light separation unit includes a reflective part and a second transmission part. Given that the optical axis of light which is incident on the first optical surface and exits the second optical surface is defined as a center axis and that an area that has an outer peripheral surface the same distance away from the center axis as the radius of the first optical surface or the second optical surface, whichever is greater, is defined as an optical effective area, the first transmission part and the second transmission part are located within the optical effective area.