<p>Biomass-derived carbon materials have attracted growing attention as sustainable and cost-effective alternatives to conventional materials for technological applications. This review explores their potential in two key domains: (i) recovery of precious metals from industrial waste and (ii) energy storage in devices such as supercapacitors and batteries. It covers various biomass sources, synthesis methods, and the structural and chemical properties that govern performance. Key conversion techniques such as pyrolysis and hydrothermal carbonization are analyzed in relation to porosity, conductivity, and surface functionality. The review discusses the mechanisms of adsorption-based metal recovery, including ion exchange and chelation, as well as the electrochemical behavior of these materials in energy storage, focusing on charge capacity and cycling stability. Distinct from earlier reviews that typically address these areas separately, this paper offers a unified framework linking the structure–function design rules across both applications. It highlights recent advances in hybrid material design, heteroatom doping, and scalable synthesis strategies with emphasis on dual-function performance and cross-application optimization. Additionally, this paper also identifies critical challenges related to material optimization, scalability, and environmental impact. Future research directions are proposed to enhance the multifunctional utility of biomass-derived carbons in sustainable technologies.</p>