Cactus (Opuntia ficus-indica), a medicinal plant thriving in arid regions, has garnered increasing interest for its potential in diabetes management due to its rich array of bioactive compounds. This review synthesizes recent advances in understanding the anti-diabetic properties of cactus constituents, particularly polysaccharides, flavonoids, vitamins, and betaines. Compelling evidence indicates that these components exert hypoglycemic effects through multifaceted mechanisms, including enhanced insulin sensitivity, protection of pancreatic beta-cells, inhibition of intestinal glucose absorption, and modulation of gut microbiota. Beyond glycemic control, cactus extracts demonstrate significant potential in alleviating diabetic complications, such as nephropathy, retinopathy, and cardiovascular disorders, attributed to their potent antioxidant and anti-inflammatory activities. This comprehensive analysis not only consolidates the mechanistic insights into cactus bioactives but also highlights its promise as a dietary intervention and a source for developing functional foods and nutraceuticals. Further research, particularly well-designed clinical trials, is warranted to validate its efficacy and translate these findings into practical diabetes management strategies.