The Ti-pillared clay-supported vanadia − ceria (yV4Ce/Ti-PILC, y was the V weight percentage (wt%), Ce weight percentage = 4 wt%) samples were prepared using the impregnation method. The catalytic activity for the selective catalytic reduction of NO_x with NH₃ (NH₃-SCR) decreased in the order of 1V4Ce/Ti-PILC > 4Ce/Ti-PILC > 2V4Ce/Ti-PILC > 1 V/Ti-PILC > 1V4Ce/Clay > Ti-PILC > Clay, with the 1V4Ce/Ti-PILC sample exhibiting the best activity (NO_x conversion >90% at 280–450 °C). Physiochemical properties of the samples were investigated by means of XRD, N₂ absorption-desorption, SEM, H₂-TPR, NH₃-TPD, XPS, and in situ DRIFT techniques. The vanadia was uniformly dispersed on the Ti-PILC support, while the ceria were mainly present in CeO₂. The Ti-pillared support was suitable for dispersing the V-Ce composite oxides. The strong interaction between vanadia and ceria led to increased H₂ consumption and high-temperature reduction. The Ce⁴⁺/Ce³⁺ and V⁵⁺/V⁴⁺ redox cycle (V⁴⁺ + Ce⁴⁺ ↔ V⁵⁺ + Ce³⁺) accounted for the excellent NH₃-SCR catalytic performance of the 1V4Ce/Ti-PILC sample. The doping of a proper amount of vanadia could promote formation of Ce³⁺ on the surface of 1V4Ce/Ti-PILC, and the formed Ce³⁺ could generate a more amount of the chemisorbed oxygen species that favored the NH₃-SCR reaction. Furthermore, the 1V4Ce/Ti-PILC sample possessed high catalytic acidity and strong NH₃ adsorption ability, which were responsible for high NO conversion in a wide range of temperatures. The NH₃-SCR reaction on the 4Ce/Ti-PILC and 1V4Ce/Ti-PILC samples obeyed the Langmuir–Hinshelwood (L–H) and Eley-Rideal (E–R) mechanisms, with the former being dominant.