The present invention relates to an optical waveguide comprising a lower cladding layer, a patternized core layer and an upper cladding layer, wherein a striking part for positioning is provided in one end part thereof, and an optical path turning mirror face is formed in a position different from a striking part-forming end part in the above core layer.Capable of being provided are an optical waveguide and an optoelectronic circuit board each having a simple configuration in which an optical device is not mounted on an optical wiring part or an optoelectronic composite wiring part and capable of connecting an optical device with a core of an optical waveguide in an optical wiring part (optical waveguide) or an optoelectronic composite wiring part (optoelectronic circuit board) at a high position accuracy and an optical module comprising an optical waveguide or an optoelectronic circuit board and a connector.