The photocatalytic CO2 reduction reaction (CRR) represents a promising route for the clean utilization of stranded renewable resources, but poor selectivity resulting from the competing hydrogen evolution reaction (HER) in aqueous solution limits its practical applicability. In the present contribution a photocatalyst with hydrophobic surfaces was fabricated. It facilitates an efficient three‐phase contact of CO2 (gas), H2O (liquid), and catalyst (solid). Thus, concentrated CO2 molecules in the gas phase contact the catalyst surface directly, and can overcome the mass‐transfer limitations of CO2, inhibit the HER because of lowering proton contacts, and overall enhance the CRR. Even when loaded with platinum nanoparticles, one of the most efficient HER promotion cocatalysts, the three‐phase photocatalyst maintains a selectivity of 87.9 %. Overall, three‐phase photocatalysis provides a general and reliable method to enhance the competitiveness of the CRR. A photocatalytic CO2 reduction reaction (CRR) in aqueous solution is a promising reaction route, while severe H2 generation (HER) greatly limits its selectivity and activity. A strategy to obtain a three‐phase contact of CO2 (gas), H2O (liquid) and catalyst (solid) is described to overcome the mass transfer limitation of CO2, elevate the CO2 concentration on the catalyst surface, restrain the HER, and enhance the activity and selectivity of the CRR.