Millets, frequently referred to as “ancient grains,” have been a staple for human civilizations across Asia, Africa, and parts of Europe for thousands of years. Despite their historical importance, these hardy cereals experienced a decline during the Green Revolution, largely due to shifts in dietary preferences, the advent of industrialized agriculture, and inadequate policy oversight. Recently, millets have become popular again. They are good for the environment and full of nutrients. Millets can help with problems like poor nutrition, health issues from modern lifestyles, and damage to the environment. This chapter provides a thorough examination of the development, agronomic and nutritional significance, socio-economic impact, technological progress, and policy frameworks that are facilitating the global resurgence of millet. The chapter underscores the remarkable adaptability of millets to marginal environments, their comprehensive nutrient profile encompassing fiber, protein, iron, and calcium, and their contribution to enhancing rural livelihoods and promoting gender equity. Technological advancements in processing, preservation, and product development have significantly improved the marketability, shelf life, and functional applications of millets. Concurrently, global policy initiatives, along with national nutrition programs, have bolstered their contribution to food security. In alignment with several Sustainable Development Goals, millets serve as a conduit between traditional knowledge and contemporary sustainability initiatives. This chapter underscores that the global resurgence of millets represents not merely a return to heritage crops but a strategic advancement toward resilient, health-promoting, and environmentally sustainable food systems.