A handrail wall mount adapter for mounting a handrail wall mounting bracket of a handrail assembly to a wall, the bracket including a mounting plate having a plurality of mounting openings, the adapter comprising: a body having at least one unthreaded opening for receiving a wall mounting fastener and a plurality of bracket mounting openings for receiving at least one bracket mounting fastener, the body being selectively positionable relative to the mounting plate in a first orientation in which the at least one unthreaded opening is aligned with the mounting openings to allow the mounting fasteners to extend through the mounting openings and through the unthreaded openings and securely engage the wall, and in a second orientation in which the bracket mounting openings are aligned with the mounting openings of the mounting plate to secure the mounting bracket to the adapter using the bracket mounting fasteners.