Homogeneously dispersed small noble metal nanoparticles such as Pt and Au supported on ordered mesoporous carbon nanospheres have been successfully synthesized via a facile hydrothermal method without using any capping agent and further post-treated with reducing agent. The average sizes of the Pt and Au nanoparticles are estimated to be ∼1.7 and ∼5 nm. The small size of the nanoparticles and short length channels of mesopores greatly improve their catalytic properties. As proof-of-concept, the catalytic performances of the mesoporous metal/C composites are investigated using the reduction of 4-nitrophenol as a model reaction. Furthermore, the catalytic activity of the obtained catalysts for oxidation of benzyl alcohol to benzoic acid in the presence of O2 at 60 °C is also investigated. The results demonstrate that such mesoporous carbon supported metal nanoparticles can be used as reusable catalysts with high catalytic activity.