The lighting control device includes a controller, a diagnosis circuit, a latch circuit, and a logic circuit. The controller outputs a control signal. The diagnosis circuit outputs an irregular signal. The latch circuit decides a state of a forcibly lighting signal. The logic circuit controls a light source in accordance with an ignition signal, the control signal, and the forcibly lighting signal. The logic circuit turns on the light source in accordance with the ignition signal while receiving the forcibly lighting signal, and turns on the light source in accordance with the control signal while not receiving the forcibly lighting signal.