Nonaqueous aluminum-ion batteries (AIBs) are emerging as a viable postlithium energy-storage technology, leveraging the high theoretical capacity, safety, and elemental abundance of aluminum. However, the practical implementation of AIBs is predominantly hindered by the limited electrochemical performance of the cathode materials. This review provides a comprehensive and systematic analysis of recent advances in cathode materials for nonaqueous AIBs. We first elucidate the fundamental aluminum-storage mechanisms and then critically assess the progress across various material classes, including carbon-based architectures, transition-metal chalcogenides and oxides, organic compounds, engineered heterojunctions, and metal–organic/covalent organic frameworks and their derivatives. The discussion focuses on the intricate structure–property relationships governing key electrochemical metrics such as the capacity, cyclability, and rate performance. Finally, we highlight the persistent scientific and technical challenges within the field and propose strategic research directions for the rational design of next-generation, high-performance cathodes. This review offers critical insights and valuable guidance for the future development of practical nonaqueous AIBs systems.