A light source apparatus includes a light source, a first wavelength selection element, a light-collecting element, a second wavelength selection element, a wavelength conversion element. The first wavelength selection element is disposed at a position where the first light is incident and having a reflective portion that reflects the first light and a transmissive portion that transmits the first light, the first wavelength selection element transmitting a second light. The light-collecting element is disposed at a position to receive the first light reflected by the first wavelength selection element. The second wavelength selection element transmits or reflects, depending on its rotation state, the first light collected by the light-collecting element. The first light incidence on the second wavelength selection element and the first light reflected by the second wavelength selection element pass through spatially different positions in the light-collecting element.