A vehicle door lock device includes a lock/unlock unit including a lock/unlock mechanism switching whether to transmit a door opening operation to a latch mechanism; and a transmission unit transmitting a lock/unlock operation to the lock/unlock unit. Further, the lock/unlock unit includes a main case housing the lock/unlock mechanism and supporting the latch mechanism, an input member having a rotation shaft passing through the main case, being coupled to the lock/unlock mechanism in the main case, and having an external coupling part outside the main case; and a cover closing an opening of the main case, the transmission unit includes a coupling member coupling a turned member to the external coupling part, and a sub case housing the coupling member, and the external coupling part protrudes from the main case in a vehicle outside direction in a state where the main case is attached to the door.