A circuit board includes a substrate, a driver circuit, at least one light-emitting element, a grounding circuit, and an antenna unit. The substrate includes a first circuit layer and a second circuit layer. The driver circuit is located on the first circuit layer. The light-emitting element is located on the first circuit layer and is electrically connected to the driver circuit, so that the driver circuit controls the light-emitting element to emit light. The grounding circuit is located on the second circuit layer and is electrically connected to the driver circuit. The grounding circuit includes a plurality of conductive traces, and the conductive traces are arranged toward one side to form a clearance area on the second circuit layer. The antenna unit is located on the first circuit layer and corresponds to the clearance area to receive and transmit a radio frequency signal.