The lighting device includes a control circuit performing dimming control of dimming a light source device according to a desired dimming level. In the dimming control, the control circuit sets a desired current value of amplitude control to a value corresponding to the desired dimming level, and set a desired duty cycle of pulse width modulation control to a predetermined value associated with a dimming subrange containing the desired dimming level, of multiple different dimming subranges of a total dimming range of the light source device. The predetermined value is a duty cycle allowing luminance of the light source device to be equal to upper limit luminance of the associated dimming subrange under a condition where the current value of the current of the light source device is a maximum value.