<p>The global food packaging sector faces a critical challenge in balancing functionality with environmental sustainability, as petroleum-based plastics contribute significantly to persistent pollution. This systematic review synthesizes advances in biodegradable nanocomposites derived from agricultural waste as a strategy addressing both waste valorization and packaging sustainability. Analyzing 25 peer-reviewed studies (2015–2025), we demonstrate that nanoscale reinforcements (nanocellulose, lignin nanoparticles, silver nanoparticles) extracted from diverse agro-wastes (pea hulls, pineapple peels, walnut shells) markedly enhance packaging performance. Key improvements include tensile strength increases up to 50.8%, reduced oxygen/moisture permeability, and active functionalities like antimicrobial efficacy (&gt; 99.99% pathogen reduction) and UV-blocking. However, challenges persist, including nanoparticle aggregation, humidity sensitivity compromising barrier properties, and scalability limitations in nanomaterial production. While biodegradability under controlled conditions is validated, real-world validation in industrial composting remains scarce. The integration of agro-waste supports circular bioeconomy principles, yet economic viability and regulatory frameworks require further development. This review emphasizes the potential of waste-derived nanocomposites for sustainable packaging but highlights the necessity for scalable synthesis, moisture-resistant designs, and comprehensive lifecycle assessments to transition from innovation to mainstream application.</p> Graphical Abstract <p></p>