Broccoli (Brassica oleracea) is a highly nutritious cruciferous vegetable, renowned for its abundant content of essential vitamins, minerals, and bioactive compounds that promote optimal health and nutrition security. Strikingly, it is an excellent source of vitamin C, which plays a critical role in immune function and skin integrity, as well as vitamin K, which is indispensable for bone metabolism and blood coagulation. Moreover, broccoli is a rich source of folate, potassium, and dietary fiber, all of which are integral to cellular processes, cardiovascular health, and gastrointestinal function. The breeding of broccoli, however, is complicated by its complex genetic makeup, biennial growth cycle, and sensitivity to environmental variations. Genomic tools such as genome-wide association studies (GWAS) and quantitative trait locus (QTL) mapping are pivotal for enhancing agronomic traits in broccoli. These methodologies facilitate the identification of genetic loci associated with key agronomical traits, including disease resistance, yield, quality, and abiotic and biotic stress tolerance. Both GWAS and QTL mapping contribute to a more comprehensive understanding of the genetic architecture underlying complex traits, thereby enabling the development of targeted and efficient breeding strategies. Ultimately, the application of these technologies is critical for developing broccoli varieties with enhanced performance across diverse environmental conditions, thereby improving productivity, quality, and resilience—factors that are essential in addressing the challenges posed by global climate change and increasing food demands.