The present invention provides an optical waveguide including an optical waveguide core for transmitting optical signals, a plate-shaped clad portion containing the optical waveguide core therein, and at least one of a concave portion and a convex portion at an end surface portion of the clad portion which end surface portion is disposed near one end of the optical waveguide core; an optical waveguide ferrule having an opening portion for receiving an optical waveguide, and at least one of a convex portion and a convex portion having a concave portion on an inner surface thereof at one end of the opening portion; and an optical connector in which the optical waveguide is inserted in the opening portion of the optical waveguide ferrule.