Mesoporous ceria–titanium catalysts were synthesized by one pot hydrothermal method and used for selective catalytic reduction (SCR) of NO with nearly complete NO conversion over a wide operating temperature range. The outstanding activity of the ceria–titanium catalyst was attributed to the tunable particle size and the efficient control of surface areas and pore volume in the range of 260–400 °C by the modulation of the soft template content. Especially, ceria oxide (CeO₂) active centers being highly dispersed and titanium oxide (TiO₂) with sufficient surface areas and uniform pore canals are the main reasons for the excellent SCR performance. For a series of catalysts, H-Ce_0.2TiO_x-2 exhibited nearly complete NO conversion (99%) in the range of 260 °C to 400 °C, with excellent stability and desired resistance to H₂O. In addition, we discussed the reaction and deactivation mechanisms of ceria–titanium catalysts for the SCR, resulting from better redox ability and abundant acid sites. In view of the simple process and outstanding stability of mesoporous ceria–titanium catalysts, this could be treated as an ideal candidate for real applications.