A circuit assembly includes: a circuit board; an inductor that is disposed on the circuit board, and that includes a coil including a winding portion made by winding a winding wire, and a core member; and a heat dissipation plate that is disposed on the opposite side of the surface of the circuit board on which the inductor is disposed, wherein a through hole is provided in a region of the circuit board that corresponds to the inductor, and a receiving protrusion that penetrates the through hole and protrudes to a surface side of the circuit board on which the inductor is disposed, and that is in heat transfer contact with the coil and the core member is provided in a region that corresponds to the through hole in the heat dissipation plate.