Light source apparatus and projector

A light source apparatus according to an aspect of the present disclosure includes a light source that outputs excitation light, a wavelength converter including a reflection layer and a wavelength conversion layer that is provided on the light incident side of the reflection layer and converts the excitation light in terms of wavelength into wavelength converted light having a wavelength band different from that of the excitation light, a first optical element that causes the excitation light from the light source to be incident on the wavelength converter, and a second optical element that is disposed in the optical path between the light source and the wavelength converter and causes at least part of reflected light of the excitation light reflected off the wavelength converter to exit toward the wavelength converter.