Optical connection component and optical connection structure

Provided is an optical connection component that is constituted of a plate-shaped substrate configured to transmit light to be used, and a resin optical waveguide. The resin optical waveguide is constituted of a resin core formed with a resin through which light to be used passes. For example, the resin core is formed with a light-cured resin. The resin optical waveguide uses air surrounding the resin core as a cladding. The resin core has a folded back structure in which the resin core once separates from the surface of the substrate and then returns to the surface of the substrate, and is connected to each of a first input/output end and a second input/output end of the substrate.