An optical waveguide includes: a center layer including at least two core layers whose edges are on substantially the same plane, and a first cladding layer provided between adjacent core layers; and a second cladding layer provided at least on both of front and rear surfaces of the center layer. At least surfaces of the core layer and the first cladding layer that are in contact with the second cladding layer include at least one resin selected from the group consisting of a resin having a hydroxyl group and a resin containing a silicon-silicon bond at a main chain thereof, and the second cladding layer includes a silicone resin.