An adaptor device to be mounted on an elongated portion of a compound archery bow, such as a cable guard, to permit carrying of the compound archery bow on a harness around the body of a user. The adaptor device utilizes a locking mechanism to lock the adaptor onto the compound archery bow. The adaptor device is connectable to a harness to allow the user to carry the compound archery bow by using only the harness. The locking mechanism is openable and closable to permit the user to attach the adaptor device to the compound archery bow for carrying, and to detach the adaptor device from the compound archery bow, such as when the user wishes to use the compound archery bow to shoot an arrow.