A wavelength conversion laser light source includes a fundamental wave laser light source (1) to generate a fundamental wave; a first mirror and a second mirror (4, 5), arranged so as to oppose each other; a wavelength conversion element (3) which is arranged between the first mirror and the second mirror and converts the wavelength of the fundamental wave; and a temperature control portion (8) to control the temperature of the wavelength conversion element. A portion of the fundamental wave is wavelength-converted in the wavelength conversion element, and moreover the fundamental wave which is not wavelength-converted is reflected by the first mirror and the second mirror and is repeatedly incident on the wavelength conversion element and is wavelength-converted, and the temperature control portion is arranged so as to be in contact with the wavelength conversion element, and the light quantity of the fundamental wave incident on the temperature control portion is reduced by a fundamental wave absorption portion (18).