A wavelength conversion laser light source having: a laser medium which generates a fundamental wave light; a laser resonator for causing laser oscillation of the fundamental wave light; a wavelength convertor which is provided with a wavelength converting region to convert the fundamental wave light under the laser oscillation by means of the laser resonator into converted light of a different wavelength; and an excitation laser light source for exciting the laser medium, wherein the laser resonator has at least one reflecting surface which reflects the fundamental wave, and a first reflecting element which is provided on an end surface of the wavelength convertor to reflect the fundamental wave light; the wavelength converting region is situated between the at least one reflecting surface and the first reflecting element; the wavelength convertor has a periodic first polarization reversal structure formed in the wavelength converting region, and a non-converting region formed between the first reflecting element and the wavelength converting region; and the non-converting region does not convert the fundamental wave light into the converted light.