Previous studies have shown that the single-crystallinity of a Pd(100) electrode surface mildly disordered by electrochemical oxidation can be reestablished if the spent surface is immersed at ambient temperatures in aqueous iodide followed by reductive desorption of the interfacial iodine. In this short note, we show that an extensively disordered (Ar+-ion-bombarded) Pd(100) surface can also be reordered by the iodine-chemisorption method. Multiple surface oxidation-reduction cycles on the ion-bombarded electrode did not regenerate an ordered surface, but the nature and/or degree of disorder was altered to resemble an anodically oxidized surface. Reordering was attained only when multiple sequences of iodine oxidative chemisorption (deposition) and reductive desorption (stripping), at potentials close to the hydrogen evolution region, were performed. Experiments were carried out in alkaline solutions to ensure that the reordering process is driven predominantly by the strong chemisorption of iodine and not by the dissolution of Pd. Electrode-surface characterization consisted of cyclic voltammetry, low-energy electron diffraction, and Auger electron spectroscopy.