This review discusses the development and application of tandem catalysts in electrocatalytic nitrate reduction (NO₃⁻RR), focusing on improving efficiency and selectivity. Tandem catalysts, which consist of multiple catalytic components working synergistically, offer promising potential for enhancing the performance of NO₃⁻RR. The review highlights recent advances in designing tandem catalysts for electrochemical NO₃⁻RR, including noble metal-related systems, transition metal electrocatalysts, and pulsed electrocatalysis strategies. Key aspects discussed include the optimization of active sites, interface engineering, synergistic effects between catalyst components, various in situ technologies, and theoretical simulations. Challenges and opportunities in the development of tandem catalysts for scaling up electrochemical NO₃⁻RR are also addressed, such as stability, durability, and reaction mechanisms. The review aims to provide insights into the mechanisms for energy sustainability and environmental safety, while outlining possible solutions for future tandem catalyst design. The nitrogen cycle plays a crucial role in sustaining life within Earth's ecosystems and industrial production. However, traditional methods for fertilizer production and agricultural practices have significantly altered the nitrogen cycle. Nitrate pollution in water poses risks to drinking water safety and human health, including nitrosamine formation, "Blue Baby Syndrome," and cancers. Ammonia, an important industrial chemical, has triggered fossil fuel consumption and sustainability concerns due to the energy-intensive Haber-Bosch process and CO₂ emissions. Therefore, electrocatalytic nitrate reduction has attracted attention as a method for simultaneous water purification and sustainable energy production. The electrochemical nitrate reduction reaction involves a complex proton-coupled electron transfer process, with options for either a five-electron reduction yielding N₂ or an eight-electron side reaction producing ammonia. The presence of diverse reaction intermediates, including ammonia, nitrite, hydrazine, hydroxylamine, nitric oxide, and nitrous oxide, adds complexity to understanding the reaction mechanism on the specific electrode surface. The conversion of nitrate to thermodynamically stable dinitrogen plays a crucial role in restoring the disrupted nitrogen cycle, while the conversion of nitrate to ammonia under ambient reaction conditions brings about the concept of waste-to-wealth. Tandem catalysts have gained significant attention in various fields, including organic synthesis, renewable energy conversion, and environmental applications. Tandem catalysts with multiple active sites enable efficient and selective transformations by utilizing intermediate species generated in one catalytic step as starting materials for subsequent steps. In recent developments, catalyst design for electrochemical nitrate reduction has embraced the concept of tandem catalysis, incorporating bimetallic catalysts with distinct "promoter" and "selector" sites to facilitate nitrite formation and nitrite reduction steps, respectively. The review discusses the mechanisms of electrochemical NO₃⁻RR, including the Vetter and Schmid pathways for high nitrate concentrations and high acidic media, and the direct mechanism for nitrate reductionThis review discusses the development and application of tandem catalysts in electrocatalytic nitrate reduction (NO₃⁻RR), focusing on improving efficiency and selectivity. Tandem catalysts, which consist of multiple catalytic components working synergistically, offer promising potential for enhancing the performance of NO₃⁻RR. The review highlights recent advances in designing tandem catalysts for electrochemical NO₃⁻RR, including noble metal-related systems, transition metal electrocatalysts, and pulsed electrocatalysis strategies. Key aspects discussed include the optimization of active sites, interface engineering, synergistic effects between catalyst components, various in situ technologies, and theoretical simulations. Challenges and opportunities in the development of tandem catalysts for scaling up electrochemical NO₃⁻RR are also addressed, such as stability, durability, and reaction mechanisms. The review aims to provide insights into the mechanisms for energy sustainability and environmental safety, while outlining possible solutions for future tandem catalyst design. The nitrogen cycle plays a crucial role in sustaining life within Earth's ecosystems and industrial production. However, traditional methods for fertilizer production and agricultural practices have significantly altered the nitrogen cycle. Nitrate pollution in water poses risks to drinking water safety and human health, including nitrosamine formation, "Blue Baby Syndrome," and cancers. Ammonia, an important industrial chemical, has triggered fossil fuel consumption and sustainability concerns due to the energy-intensive Haber-Bosch process and CO₂ emissions. Therefore, electrocatalytic nitrate reduction has attracted attention as a method for simultaneous water purification and sustainable energy production. The electrochemical nitrate reduction reaction involves a complex proton-coupled electron transfer process, with options for either a five-electron reduction yielding N₂ or an eight-electron side reaction producing ammonia. The presence of diverse reaction intermediates, including ammonia, nitrite, hydrazine, hydroxylamine, nitric oxide, and nitrous oxide, adds complexity to understanding the reaction mechanism on the specific electrode surface. The conversion of nitrate to thermodynamically stable dinitrogen plays a crucial role in restoring the disrupted nitrogen cycle, while the conversion of nitrate to ammonia under ambient reaction conditions brings about the concept of waste-to-wealth. Tandem catalysts have gained significant attention in various fields, including organic synthesis, renewable energy conversion, and environmental applications. Tandem catalysts with multiple active sites enable efficient and selective transformations by utilizing intermediate species generated in one catalytic step as starting materials for subsequent steps. In recent developments, catalyst design for electrochemical nitrate reduction has embraced the concept of tandem catalysis, incorporating bimetallic catalysts with distinct "promoter" and "selector" sites to facilitate nitrite formation and nitrite reduction steps, respectively. The review discusses the mechanisms of electrochemical NO₃⁻RR, including the Vetter and Schmid pathways for high nitrate concentrations and high acidic media, and the direct mechanism for nitrate reduction