A switching control circuit for controlling a power supply circuit that includes an inductor receiving a rectified voltage corresponding to an AC voltage, and a transistor controlling an inductor current flowing through the inductor. The switching control circuit controls switching of the transistor, and includes an output circuit, a processing circuit and a drive signal output circuit. The output circuit sequentially receives a first voltage, which fluctuates at a frequency twice a frequency of the AC voltage, and outputs, as a second voltage, the received first voltage after a delay of a predetermined period of time. The processing circuit processes the first voltage based on a value corresponding to the second voltage, to remove a ripple component generated in an output voltage and contained in the first voltage. The drive signal output circuit outputs a drive signal for driving the transistor, in response to a processing result of the processing circuit.