Tuning the interfacial perimeter and structure is crucial to understanding the origin of catalytic performance. This paper describes the design, characterization, and application of CeO₂ modified Au@SBA-15 (Au–CeO₂@SBA-15) catalysts in selective oxidation of benzyl alcohol. The reaction results showed that Au–CeO₂@SBA-15 catalysts exhibited higher catalytic activity compared with Au@SBA-15 and Au/CeO₂ catalysts under identical conditions along with the high selectivity towards benzaldehyde (>99%). The turnover frequency of benzyl alcohol over the Au–100CeO₂@SBA-15 catalyst is about nine-fold and four-fold higher than those of Au@SBA-15 and Au/CeO₂ catalysts, respectively. The supported catalysts were characterized by N₂ adsorption–desorption, inductively coupled plasma optical emission spectroscopy, X-ray diffraction, transmission electron microscopy, high-angle annular dark-field scanning transmission electron microscopy, scanning transmission electron microscopy-energy dispersive spectrometry, and X-ray photoelectron spectroscopy. It was found that the Au and small CeO₂ nanoparticles (∼5 nm) were homogeneously mixed in the channels of SBA-15, which led to an increase in the interfacial area between Au and CeO₂ and consequently a better catalytic performance of Au–CeO₂@SBA-15 catalysts for the selective oxidation of benzyl alcohol to benzaldehyde compared with that of Au/CeO₂. The prevention of agglomeration and leaching of Au nanoparticles by restricting them inside the mesopores of SBA-15 was conducive to the stable existence of large quantities of Au–CeO₂ interface, which leads to high stability of the Au–CeO₂@SBA-15 catalyst.