Provided is a circuit assembly in which the mounting area of a substrate can be increased. A circuit assembly includes an electronic component having a plurality of terminals, a conductive member for supporting the electronic component (10), at least one of the terminals of the electronic component being electrically connected to the conductive member, and a substrate provided with a conductive pattern to which another terminal of the electronic component is electrically connected, in which the substrate is fixed to a surface of the conductive member that is opposite to a surface of the conductive member that supports the electronic component.