A projection apparatus and a light source apparatus are provided. The light source apparatus includes at least one first light source, at least one second light source, a wavelength conversion device, and a filter device. The wavelength conversion device is disposed on a transmission path of the first light beam from the first light source, and converts the first light beam into a conversion light beam. The filter device corresponds to the wavelength conversion device and is disposed between the first light source and the wavelength conversion device and disposed between the second light source and the wavelength conversion device. The filter device allows the first light beam and the conversion light beam to pass through, and reflects the second light beam. The projection apparatus and the light source apparatus have favorable light source utilization efficiency.