In an elevator car door locking apparatus, a doorstop-side blade is disposed on a car door by a linking mechanism, and is displaceable horizontally between a locked position, and an unlocked position that is further away from a door pocket than the locked position. A balance weight is disposed on an opposite side of the pivoting shaft of the link from the doorstop-side blade. The doorstop-side blade comes into contact with a landing door engaging member and displaces, and the balance weight also displaces away from the doorstop-side blade, due to the car door moving toward the door pocket side when a car is in position at a floor.