Described is a portable sun visor comprising a sun shielding member, an adjustable support arm, and a mounting member, said mounting member comprising a plurality of different attachment members for fastening the sun visor to an object. One of the attachment members is a clamp featuring a stationary first jaw that is defined by a handle portion of the mounting member near a distal end of the handle that lies opposite the support arm, and a movable second jaw pivotally connected to the handle portion at an intermediate location thereon. The mouth of the clamp points toward the distal end of the handle portion, where a blade extends parallel to the handle on a side thereof opposite the clamp. The blade is insertable into a vehicle door on the inside surface of a window to hold the sun shielding member in position at that window.