We propose a new structure of a viewing angle controllable liquid crystal display (LCD) consisting of a conventional liquid crystal display (LCD) panel and a thermally variable retardation layer (TVRL) established by uniformly aligned LC cell with transparent indium-tin-oxide electrodes for Joule heating. In the TVRL, nematic phase is transitioned into the isotropic one by Joule heating. From numerical simulations, the intrinsic wide viewing angle was achieved at the isotropic phase of the TVRL by Joule heating, while the narrow viewing angle was obtained at the nematic phase of the TVRL. The structure of the viewing angle control proposed here is adoptable to all LCD modes with the wide viewing angle characteristics.