A lighting circuit that is for a lamp including an LED as a light source and that includes a resonant circuit that can be designed with ease. A lighting circuit 11 is for a lamp including a light-emitter 39 composed of an LED as a light source. The lighting circuit comprises: a rectifier circuit 31 that rectifies power supplied from an alternating current power supply via a base 28; an inverter circuit 33 connected to an output side of the rectifier circuit 31 and outputting alternating power to the LED; and a resonant circuit 35 connected to an output side of the inverter circuit 33, wherein the resonant circuit 35 includes an inductor L and a capacitor C1 and is connected in series with the light-emitter 39, the inductor L and the capacitor C1 being connected in series.