Abstract: A one-piece post anchor for securing a post to a support structure including four identically shaped side members, each member comprising a curvilinear planar member having a concave shape extending from a top edge outwardly to a bottom-edge. The four side members are positioned in a rectangular pattern with the top edges forming a rectangular opening, and the bottom edges forming a rectangularly-shaped base. The base has a cross-sectional area greater than the cross-sectional area of the rectangular opening. Further, four identically shaped interior members are positioned in a rectangular pattern within the rectangular opening to form a rectangular channel through the post anchor. A plurality of support flanges are fastened to each interior member and corresponding side member for additional structural support. Openings are provided in each side member to receive a screw for mounting the post anchor to a post and to the support structure.