Fuente: Agri-Waste and Microbes for Production of Sustainable Nanomaterials Conventional plastics, a synthetic polymer derived predominantly from petroleum-based sources, pose one of this era’s most environmental challenges. Therefore, steady interest has been concentrated on biopolymersBiopolymers, bio-based carbon materials from renewable natural biomass, as promising eco-friendly and sustainable alternatives. This chapter reviews recent peer-reviewed literature—mainly from 2018 to 2025—on valorizing agro-based residues and organic waste, including lignocellulosic biomassLignocellulosic biomass, food waste, and emerging feedstocks such as microbial, algal, and insect-derived polymersInsect-derived polymers into sustainable materials. BiopolymersBiopolymers offer interesting application choices due to their benefits (biodegradabilityBiodegradability, improved mechanical properties, and antibacterial effects), making them promising sustainable alternatives to petroleum-based plastics. Green synthesis methods, such as enzymatic processes, microbial fermentationMicrobial fermentation, and nanotechnologyNanotechnology, further enhance their functionality and environmental performance, aligning with the global development goals. Moreover, active and smart packaging businesses depend on biopolymer—materials that can enhance safety and extend the shelf life of food products. Beyond general industrial use, requiring cross-disciplinary cooperation and supportive legislative frameworks, high production costs, scaling challenges, and legal restrictions are significant barriers to adopting large-scale biopolymersBiopolymers.