Feiyue Zhang, Chaoqun You, Lingchao Cai, Fei Wang
ABSTRACT Aerogels, characterized by their ultra‐lightweight nature and highly porous architecture, demonstrate immense application potential across diverse sectors due to outstanding thermal insulation, superior mechanical properties, and versatile functionality. In recent years, bio‐based aerogels have emerged as a leading frontier in sustainable materials research, leveraging their renewability, minimal environmental impact, and broad applicability. This review comprehensively summarizes recent advancements in bio‐based aerogels derived from natural polymers—such as cellulose, chitosan, and alginate—with a focused analysis of innovative preparation techniques, including freeze‐drying, supercritical drying (SCD), and advanced crosslinking strategies. Their multifunctional applications in water purification, energy storage, biomedicine, and related fields are critically evaluated. The review further identifies key challenges—such as scalability, performance optimization, and material stability—and outlines future directions, emphasizing that intelligent responsiveness, green circular technologies, and multifunctional integration are pivotal to advancing next‐generation bio‐based aerogels.