Abstract Synthesis of formate from hydrogenation of carbon dioxide (CO 2 ) is an atom‐economic reaction but is confronted with challenges in developing high‐performance non‐precious metal catalysts for application of the process. Herein, we report a highly durable edge‐rich molybdenum disulfide (MoS 2 ) catalyst for CO 2 hydrogenation to formate at 200 °C, which delivers a high selectivity of over 99 % with a superior turnover frequency of 780.7 h −1 surpassing those of previously reported non‐precious metal catalysts. Multiple experimental characterization techniques combined with theoretical calculations reveal that sulfur vacancies at MoS 2 edges are the active sites and the selective production of formate is enabled via a completely new water‐mediated hydrogenation mechanism, in which surface OH* and H* species in dynamic equilibrium with water serve as moderate hydrogenating agents for CO 2 with residual O* reduced by hydrogen. This study provides a new route for developing low‐cost high‐performance catalysts for CO 2 hydrogenation to formate.