Noble metal nanoparticles have attracted considerable attention due to their useful capabilities as heterogeneous catalysts. However, they are usually prepared using various organic stabilizing agents that negatively affect their catalytic activities. Herein, we report a facile, clean, and effective method for synthesizing supported ultrafine noble metal nanoparticles by utilizing the reductive property of a new pyrochlore oxide: Sn1.06Nb2O5.59F0.97 (SnNbOF). Ultrafine Au, Pd, and Pt nanoparticles or clusters are homogeneously distributed on the SnNbOF surface. In addition, the atomic cavities and ion exchange properties of pyrochlore-type SnNbOF can facilitate the synthesis of atomic Ag dispersed within the framework of SnNbOF. Noble metal SnNbOF hybrids can be obtained in one step at room temperature, and no foreign reducing agents or stabilizing organics are required for the synthesis. We also show that the fabricated hybrids exhibit promising photocatalytic properties for ethylene oxidation and CO2 reduction.