Millets, encompassing both major types such as sorghum, pearl millet, and finger millet, and minor types including foxtail millet, kodo millet, and barnyard millet, are increasingly recognized for their resilience, nutritional richness, and associated health benefits. The nutritional and functional properties of these ancient grains, however, are significantly influenced by modern processing technologies. This chapter highlights the nutritional composition of major and minor millets, their inherent bioavailability of nutrients in raw form, and the transformative effects of innovative processing methods on their quality. Advanced techniques such as controlled thermal processing, enzyme-assisted processing, infrared heating, high-pressure processing (HPP), pulsed electric field (PEF), pulsed light, ultrasound, cold plasma, radiofrequency heating, ohmic heating, microwave-assisted treatments, bio-elicitation, and hurdle technologies are explored for their role in modifying nutritional and functional attributes of millets. These technologies can improve protein digestibility, micronutrient bioavailability, and antioxidant potential by reducing antinutritional factors such as phytates and tannins while also influencing starch structure and glycemic response. The chapter further discusses challenges in adopting these technologies for millet processing and outlines future prospects for sustainable and consumer-oriented approaches that retain the nutritional and functional integrity of millets.