AbstractRegulating the coordination environment of single‐atom sites is of high necessity to promote the catalytic performances of the photocatalysts. Herein, the preparation of atomically dispersed Co‐Ag dual‐metal sites anchored on P‐doped carbon nitride (Co₁Ag₁‐PCN) via supramolecular and solvothermal approaches is reported, which demonstrates desirable performance for photocatalytic H₂ evolution from water splitting. The optimal Co₁Ag₁‐PCN catalyst achieves a remarkable hydrogen production rate of 1190 µmol g⁻¹ h⁻¹ with an apparent quantum yield (AQY) of 1.49% at 365 nm, superior to most of the newly reported metal‐N‐coordinated photocatalysts. Systematic experimental characterizations and density functional theoretic studies attribute the enhanced photocatalytic activity to the synergistic effect of Co‐Ag dual sites with exclusive coordination configuration of Co‐N₆ and Ag‐N₂C₂, which enhances the charge density and promotes oriented electrons transport to the metal centers with reduced free energy barriers by facilitating the formation of H* intermediates as the key step in hydrogen evolution. This study reveals a versatile strategy to tailor the electronic structures of dual‐metal sites with synergies by engineering the neighboring coordination environment.