Critical metals are essential for sustaining industrial development, advancing technological innovation, and enabling the global green transition. Ensuring their sustainable extraction and recovery is crucial for reducing resource dependency, mitigating environmental impacts, and enhancing the resilience of supply chains. Conventional methods, such as oxidation roasting and pressure leaching, are often energy-intensive, environmentally burdensome, and limited in efficiency. In contrast, advanced oxidation processes, which focus on reactive oxygen species, offer a cleaner and more efficient alternative for leaching critical metals under mild conditions. This review comprehensively summarizes recent progress in the application of advanced oxidation processes for the extraction and recovery of critical metals from both primary ores and secondary resources. Key topics include the design and optimization of leaching processes, the mechanisms of reactive oxygen species generation, and the interactions between reactive oxygen species and critical metals. The sustainability of these processes is critically evaluated, highlighting their potential economic and environmental advantages. Finally, existing challenges and prospects are discussed to inform the development of sustainable, highly efficient, and environmentally benign technologies for critical metals extraction and recovery, thereby supporting the circular economy.