Manganese-based cathode materials have gained significant attention in energy storage systems due to their cost-effectiveness, abundance, and environmental friendliness. This chapter provides a comprehensive overview of the structure-property-performance relationships and electrochemical mechanisms that govern the performance of Mn-based cathodes. Key structural features, including the layered arrangement of transition metal oxides and intercalating ions, are explored in detail to explain their influence on capacity, stability, and ionic conductivity. The electrochemical processes, particularly the Mn3+/Mn4+ redox activity and its associated phase transitions are analyzed to highlight fundamental challenges such as the Jahn–Teller effect, structural degradation, and capacity fading caused by Mn dissolution. Building upon this foundation, the chapter delves into recent progress in addressing these challenges. Advances in material design are discussed, aiming at enhancing structural stability and electrochemical performance. Developments in tailoring Mn-based cathodes for alternative ion chemistries, including sodium-ion and potassium-ion batteries, are also presented, showcasing their versatility and potential for large-scale applications. This chapter provides both foundational knowledge and insights into cutting-edge research that drives the development of Mn-based cathode materialsMn-based cathode materials for next-generation energy storage technologies.