The seed plays a vital role in agriculture and acts as a carrier of the genetic potential of improved varieties. The National Agriculture Research System of India (NARS) has developed several improved millet varieties with higher yields and resistance to diseases and pests. The timely provision of high-quality seeds at affordable rates of these improved varieties to the farmers is crucial for the nutritional and food security of the nation. The present chapter discusses the genetic and agronomic principles of seed production in millets. Genetic principles such as developmental variation, mechanical mixture, mutations, natural crossing, minor genetic variation, selective influence of diseases, and breeding techniques are discussed. Various strategies for maintaining genetic purity, including controlling seed sources, land selection, and implementing isolation measures can be adopted for producing quality seeds. Agronomic principles including the suitable areas for seed production are discussed. The chapter also emphasizes the significance of the seed certification system, outlining standards and procedures for seed quality assurance. The important considerations during hybrid seed productions such as planting ratios and synchronization of flowering between parental lines to achieve synchronized flowering are provided. In conclusion, the chapter highlights the critical role of quality seeds in ensuring food security and provides various principles for quality seed production, certification, and distribution in millets.