Apparatus, devices, systems, and methods for clamping a length adjustable hook on a portable headrest with chin support to a top or side of a seat back, which is both adjustable and foldable to be portable for ease in transport. The horizontal chin rest pivotally attached to the bottom of a vertical member allows a sitting person's head to be supported in an upright position, while restricting movement both forward and side to side. The headrest can have telescoping vertical members which are length adjustable for different sized users. The chin support can have a cushion that is rotatable at different increments for comfort. The cushion can be slotted to allow the vertical member to be placed inside the slotted portion.