Provided is an optical wavelength conversion device in which heat of an optical wavelength conversion member can be dissipated efficiently while the joint strength between the optical wavelength conversion member and a heat dissipation member is maintained. In the present disclosure, the optical wavelength conversion device includes an optical wavelength conversion member configured to convert the wavelength of incident light; a heat dissipation member which is more excellent in heat dissipation than the optical wavelength conversion member; and a joint portion which joins the optical wavelength conversion member and the heat dissipation member together. The optical wavelength conversion member includes a plate-shaped ceramic fluorescent body and a reflecting film disposed on a heat dissipation member-side surface of the ceramic fluorescent body. The joint portion has a thermal conductivity of 120 W/mK or more. The joint portion has a melting point of 240° C. or higher.