The invention provides a light source apparatus including first and second light sources that output light in mutually opposing directions along a single optical axis; a wavelength conversion element that is disposed between these light sources and that generates light of a wavelength different from that of said light due to irradiation with the light; a first optical member that is disposed between the wavelength conversion element and the first light source, that transmits the light therefrom, and that reflects back light that is scattered towards the first light source, toward the wavelength conversion element; and a second optical member that is disposed between the wavelength conversion element and the second light source, that transmits the light therefrom, and that deflects, in a direction intersecting the optical axis, the light scattered toward the second light source and the light reflected back by the first optical member.