An opto-electric hybrid board is capable of being mounted on a connector having a bottom wall. The opto-electric hybrid board sequentially includes an optical waveguide and an electric circuit board toward one side in a thickness direction of these. The optical waveguide includes an under clad layer, a core layer disposed on a one-side surface of the tinder clad layer, and an over clad layer disposed on the one-side surface of the under clad layer so as to cover the core layer. The under clad layer is in contact with an other-side surface in the thickness direction of the electric circuit board. The one-side surface in the thickness direction of the electric circuit board is capable of being placed on the bottom wall.