A vehicle door lock device includes a housing including: an outer housing body including a covering portion covering an outer side of an electric motor and an outer side of a worm, an outer shaft-supporting portion supporting an active lever, and an outer shaft-supporting portion supporting a worm wheel; and an inner housing body including an inner shaft-supporting portion supporting an active lever, and an inner shaft-supporting portion supporting the worm wheel. An outer surface of the covering portion of the outer housing body and an outer surface of the outer shaft-supporting portion, which is provided in the outer housing body, for supporting the active lever, are formed in the same flat surface, and an outer surface of the outer shaft-supporting portion, which is provided in the outer housing body, for supporting the worm wheel, is formed in a dented surface dented inwardly with respect to the flat surface.