A light source device includes: a light-emitting section including plural light-emitting elements; a shifter that performs a shift operation; and a controller that causes the shifter to perform the shift operation to set, among the plural light-emitting elements, a light-emitting element which is to emit light, that changes the shifter to an OFF state after the set light-emitting element is shifted to a state in which the set light-emitting element is able to emit light, and that causes the set light-emitting element to emit light multiple times by turning ON and OFF a voltage application side of a power source, the power source supplying a light-emitting current which causes the light-emitting element to emit light.