A wavelength conversion element according to the present disclosure includes a base member having a reflecting surface, a wavelength conversion section having a first surface which excitation light in a first wavelength band enters, and a second surface opposed to the base member, and configured to perform a wavelength conversion on the excitation light into fluorescence in a second wavelength band, a holding section configured to hold the wavelength conversion section to the base member, and an air layer disposed in one of a space surrounded by a first recessed part provided to the base member so as to be opposed to the second surface of the wavelength conversion section and the second surface of the wavelength conversion section, and a space surrounded by a second recessed part provided to the wavelength conversion section so as to be opposed to the reflecting surface of the base member and the reflecting surface of the base member, wherein in the first surface, at least a part of a portion opposed to the reflecting surface and the air layer is set as an incident area of the excitation light.