Millets, a diverse group of small-grained cereals, are gaining global attention due to their remarkable nutritional benefits, climate resilience, and sustainability in agricultural systems. Despite their potential as a solution to pressing challenges in food security, climate adaptation, and malnutrition, millets remain underutilized, largely due to significant postharvest challenges. These include inefficient processing technologies, high postharvest losses, limited storage infrastructure, and short shelf life. Addressing these issues is essential to unlock the full potential of millets in sustainable food systems. This review highlights the major challenges in millet postharvest management, emphasizing the need for innovative and sustainable solutions. Emerging technologies such as hermetic storage, smart packaging, and digital tools are transforming millet value chains, enhancing their quality and marketability. Sustainable practices, including renewable energy-based processing, biodegradable packaging, and circular economy models, are further advancing environmental and economic sustainability. Additionally, case studies illustrate the practical applications of these approaches in various contexts, showcasing their scalability and impact. The review also identifies key research gaps and future directions, including the need for multidisciplinary approaches to enhance millet postharvest technologies, and improve value chain efficiency. By addressing these challenges holistically, millets can play a critical role in achieving global food security.