A vehicle door lock apparatus (1) includes a latch housing (9), a latch mechanism (8), an actuating housing (7), and an actuating mechanism (6). The actuating housing (7) includes a first housing (70) made of resin joined to a second housing (80) made of resin, thereby forming a housing chamber (7A). The first housing (70) includes at least one projection (75P, 75Q, 75R, and 75S) that extends toward the second housing (80) from a proximal end (75A) to a distal end (75B). The second housing 80 includes at least one receptacle (85P, 85Q, 85R, and 85S) having a contact part (85A) welded to the distal end (75B).