<p>Aqueous rechargeable batteries (ARBs) are promising candidates for large-scale energy storage due to their inherent safety and low cost. However, their development is largely constrained by the structural instability, sluggish reaction kinetics, and narrow electrochemical window of conventional cathode materials. In this context, high-entropy cathode materials have recently emerged as a powerful strategy to stabilize crystal frameworks and modulate electrochemical processes in aqueous environments. This review focuses on the design principles, entropy-stabilization mechanisms, and electrochemical functionalities of high-entropy cathodes for ARBs. Representative material systems, including Prussian blue analogues, high-entropy oxides, polyanionic compounds, and catalytically active cathodes, are critically discussed across various charge carriers. Finally, the remaining challenges and future directions for high-entropy cathode materials are highlighted, with particular emphasis on scalable synthesis, mechanistic understanding, full-cell validation, and cost-effective elemental design. This review aims to provide targeted insights into entropy-driven cathode design for next-generation aqueous energy storage systems.</p>