Abstract: The invention is a support and retainer fixture for hollow fence posts. Angle irons extending up from a bottom plate are oriented with their corners on the inside of the structure and their legs pointed outward. The top ends of the angle irons are cut at a slope with the inside edges being lower than the outside edges. A top plate with a center hole has edges which are bent upward to match the angles formed on the ends of the angle irons and is held in place by a center threaded stud. When a hollow post is slipped down over the assembly and a nut tightened down onto the top plate, the top plate's edges force the top ends of the angle irons out toward the inside surface of the hollow post, locking it in place.