An optical receptacle includes a first optical surface which receives incidence of light, a reflecting surface which reflects light along a substrate, a light separating section which separates light from the reflecting surface into monitor light and signal light, a second optical surface which emits the monitor light toward a light receiving element, and a third optical surface which emits the signal light. The light separating section includes a plurality of separating units each including a vertical splitting transmissive surface, an inclining splitting reflecting surface and a parallel splitting stepped surface. In the light separating section, 4 to 6 separating units are disposed within a region where light reflected at the reflecting surface is incident. A height of a boundary between the splitting transmissive surface and the splitting stepped surface with respect to a virtual plane including the splitting reflecting surface is 13 to 21 μm.