Carbon materials-supported metal catalysts are of great significance to the renewable energy conversion. More than a support to immobilize metal nanoparticles and improve atomic usage, the carbon materials can also impact the catalysis performance in a way of engineering the electronic structure of active metal components. The modulation of such an electronic metal−support interaction (EMSI) for designing efficient catalysts has been a hotspot in recent years. Benefiting from the development of advanced characterization techniques and theoretical simulations, one can shed light on the key points regarding EMSI and construct the relationship between EMSI and catalysis performance. In this Review, we summarize the recent work concerning the electronic interaction between carbon supports and metals, and discuss the underlying factors, including the nature of metal, metal morphology, metal particle size, carbon structure, heteroatom doping, carbon coating, and interfacial binding. The relationship between EMSI and the catalytic performance, by taking hydrogen/oxygen electrocatalysis for examples, is highlighted. These summaries would deepen the understanding of EMSI and favor the progress of carbon-supported metal catalysts.