A light source apparatus includes a light source, a substrate provided rotatably around a predetermined axis of rotation, a scattered light generator which is provided on the substrate and on which light from the light source is incident, a pickup lens provided on the light exiting side of the scattered light generator, and a holding member that holds the pickup lens, and at least one of the contour of a surface closest to the substrate among the surfaces of the holding member and the contour of a surface facing the substrate among the surfaces of the pickup lens is located inside the contour of the substrate when viewed in the direction parallel to the axis of rotation.