A wavelength conversion unit includes a wavelength conversion member that transmits a part of incident excitation light and converts a part of the excitation light into wavelength-converted light having a wavelength different from a wavelength of the excitation light to emit the wavelength-converted light. The excitation light has an intensity distribution in which an intensity is maximum at the center and decreases as getting apart from the center. A thickness of the wavelength conversion member at a portion into which light at the center of the intensity distribution of the excitation light enters is larger than those at any other portions.