A light source apparatus according to an aspect of the present disclosure includes a first light source that emits first light, a second light source that emits second light, a light guide that causes the first light emitted from the first light source to propagate, a wavelength converter containing a phosphor that emits fluorescence when excited with the second light emitted from the second light source, and a light combiner that combines the first light having exited out of the light guide with the fluorescence having exited out of the wavelength converter. The light guide and the wavelength converter are disposed side by side. The light guide has a first end section and a second end section. The wavelength converter has a third end section and a fourth end section. The first light enters the light guide via the first end section thereof.