A power-supply control apparatus includes a controller that is configured to perform duty control on a switch device which forms an output stage of a switched-mode power supply which is configured to generate an output voltage from an input voltage. The controller has an OFF-skip function to skip cyclic OFF transitions of the switch device. The controller keeps the switch device turned ON by ignoring a reset signal based on feedback control on the output voltage under a state in which the OFF-skip function is implemented.