A wavelength conversion device according to an embodiment of the present disclosure includes a first base member, a second base member opposed to the first base member, and a phosphor layer with which a first space is filled. The second base member has a surface opposed to the first base member. The surface has an annular recessed portion. The recessed portion includes therein a plurality of protruding portions extending from an inner peripheral portion toward an outer peripheral portion. The first space is formed by the first base member and the recessed portion of the second base member.