Photo-assisted selective catalytic reduction (photo-SCR) has been considered as a promising strategy for NOx removal in recent decades. The purpose of the present work was to test the effectiveness of La1–xPrxCoO3, supported on the surface of natural palygorskite (Pal) by a facile sol-gel method, as a photo-SCR for the removal of NOx from wastewaters. The structure, acidity, and the redox property of the prepared La1–xPrxCoO3/Pal nanocomposite were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Visible diffuse reflectance spectroscopy (UV-Vis DRS), and X-ray photoelectron spectroscopy (XPS). Density functional theory (DFT) calculations were employed to determine the valence bands. The La1–xPrxCoO3/Pal catalysts were then tested for SCR removal of NOx with the assistance of photo-irradiation. The photo-SCR results revealed that the NOx conversion and the N2-selectivity were greatly improved by this method and reached >95% when carried out at the relatively low temperature of 200°C and with the Pr doping at x = 0.5. The improvements were attributed to the co-precipitation of a PrCoO3 phase as in a solid solution forming a coherent heterojunction of PrCoO3/La0.5Pr0.5CoO3 on the Pal surface.