The global pursuit of sustainable energy and green chemical production has intensified interest in lignocellulosic agro-wastes as feedstocks for bio-based chemicals and biofuels. Millet-derived residues, including straw, husks, and bran, represent an underutilized yet abundant biomass source that can provide economic and environmental benefits. This study investigates the valorization potential of millet agro-waste for bioenergy and chemical production, emphasizing green, cost-effective, and scalable processes. A multi-disciplinary approach integrating nanotechnology, biocatalysis, and polymer chemistry is applied to examine functional transformation pathways. Notably, the role of biogenic nanoparticles in enhancing conversion efficiency, antimicrobial properties, and antioxidative potential is highlighted (Abdelbaky et al., 2022; Abasi et al., 2022). Millet residues are characterized for their physicochemical properties, including cellulose, hemicellulose, lignin content, and inherent bioactive compounds, providing a foundation for bio-based material synthesis and energy applications (Deshwal & Singh, 2025). The review synthesizes previous studies on enzymatic, chemical, and physical processing strategies, illustrating the comparative advantages and limitations of each approach (Lastowka et al., 2005; Lodish et al., 2000; Maffia, 2003). Analytical frameworks for optimizing process yield, energy balance, and environmental footprint are discussed. Results indicate that millet agro-waste can be efficiently converted into bioethanol, biogas, and biopolymers while offering secondary benefits such as soil amendment and nutrient recovery. Furthermore, the incorporation of nanoscale catalysts and biogenic nanoparticles significantly improves reaction kinetics, selectivity, and product stability (Ganapathy et al., 2023; He et al., 2022; Mubeen et al., 2023). Critical gaps remain regarding large-scale implementation, techno-economic feasibility, and lifecycle environmental impacts. This paper positions millet residues as a strategic feedstock for circular bioeconomy initiatives, providing actionable insights for researchers, policymakers, and industry stakeholders. The findings underscore the dual potential of millet agro-waste to contribute to renewable energy production and high-value chemical manufacturing, fostering sustainable development goals in resource-limited agricultural regions.