Proso millet (Panicum miliaceum L.) is an ancient crop cultivated by humankind in the Neolithic era. The crop was domesticated in China, spread to Central Asia, and later to Europe and North America. It is a short-duration C4 crop with inherent biotic and abiotic stress tolerance and has vast potential for climate change and sustainable agriculture. Short-duration and shallow root systems make it suitable for use in any cropping system. Proso millet grains are rich in protein 13–18%, magnesium, and phosphorus. It is an important crop of the past that has found its place in genebanks worldwide. A large number of accessions collected from tropical, subtropical, and temperate regions are conserved in the genebank globally. These accessions are invaluable and harbor important genes for agronomic and adaptive traits. Collection, conservation, and characterization of germplasm are very important for cataloguing and further utilization for trait-specific breeding. Conventional breeding has provided many varieties of proso millet, utilizing the available genetic resources. However, the genetic gains were not significant in the yesteryears. Advances in genetics and plant breeding, including genomics and biotechnology, can complement the conventional breeding strategies. The use of biotechnology, such as marker-assisted selection, genome-wide association studies, genomic selection, and genome editing, will enable a wider scope for trait-specific breeding in proso millet. The proso millet genome sequencing has opened avenues for “omics” studies for full utilization of genomic resources for plant breeding and development of climate-resilient and nutrient-rich cultivars.