Abstract: A head rest assembly for a chair includes a head rest that can be adjusted in as many as three manners, such as rotational, horizontal, and/or vertical adjustment, with respect to a chair in a generally upright orientation, to achieve a desired position. The user can adjust the position of the head rest by grasping the head rest and applying force(s) in the desired directions(s), and the head rest remains in the desired position by friction, without needing to actuate any levers, knobs, and the like. Further, the head rest can have an outer surface with variable radii of curvature, and the assembly can be removably mounted to a chair.