A rhodium-catalyzed one-pot hydroformylation of olefins with CO₂ , hydrosilane, and H₂ has been developed that affords the aldehydes in good chemoselectivities at low catalyst loading. Mechanistic studies indicate that the transformation is likely to proceed through a tandem sequence of poly(methylhydrosiloxane) (PMHS) mediated CO₂ reduction to CO and a conventional rhodium-catalyzed hydroformylation with CO/H₂. The hydrosilylane-mediated reduction of CO₂ in preference to aldehydes was found to be crucial for the selective formation of aldehydes under the reaction conditions.