Catalysts based on gold nanoparticles (Au NPs) have received much attention during the past two decades because of their unique catalytic properties in basic and applied research. Both experimental findings and theoretical predictions show that the size of the Au NPs plays a crucial role in governing their catalytic capability, with smaller Au NPs typically exhibiting higher catalytic performances. Although mesoporous silica has been extensively used as a support for Au NPs, the diffusion of reactants and products in the pores has been a challenge. Herein, we report an alternative silica material, silica NPs from rice husks (RHs), which have a rough surface, as a potential support for Au NPs. Notably, in this study, RH, a byproduct from rice production, was used as the silica source. Silica obtained by calcining HCl-treated RHs was first modified with (3-aminopropyl)triethoxysilane (APTES), which was designed to play two roles: helping the Au precursor (AuCl4-) absorb onto the silica surface and stabilizing the resultant Au NPs obtained by reducing AuCl4- using sodium borohydride (NaBH4). Characterization of the nanostructures revealed that the Au NPs formed with a narrow size distribution of ca. 2-4 nm, which is critical for catalytic applications. The reduction of 4-nitrophenol by NaBH4- with RH-silica-supported Au NPs as a catalyst was systematically studied to demonstrate the excellent catalytic performance of the prepared catalyst.