A light source apparatus according to an aspect of the invention includes a light source array including a plurality of first light emitting devices and a plurality of second light emitting devices and a light branching element that causes a first light ray flux emitted from the plurality of first light emitting devices and a second light ray flux emitted from the plurality of second light emitting devices to travel in directions different from each other. The light source array is formed of a plurality of series circuits including a first series circuit and a second series circuit. The first series circuit and the second series circuit each include at least one of the plurality of first light emitting devices and at least one of the plurality of second light emitting devices.