Opuntia is a plant that grows in wild, arid, and semi-arid regions, and it is a renowned food source that is presently undervalued. The chemical composition and properties of the Opuntia genus have attracted research and commercial interest as its species are rich in phytochemicals, nutrients, and bioactive compounds. Several of these constituents have revealed anti-inflammatory, antioxidant, antibacterial, anti-cancer, anti-atherosclerotic, antidiabetic, neurological, and gut protective characteristics. This review provides an extensive and up-to-date evidence synthesis of the nutrients in the Opuntia genus, its phytochemical composition, health benefits, the influence of the processing technologies on its bioactive components, and the potential for functional food product development. Due to its high nutritional value, Opuntia genus has the potential to contribute to improving food security and contribute to the food industry as food additive or preservative. Accordingly, Opuntia products can be utilized as food substitutes as part of a well-balanced diet and may potentially have pharmacological properties. The Opuntia genus is also used as animal feed, a source of nutraceuticals, an addition to edible packaging materials, wastewater treatment, and land rehabilitation in arid regions. Opuntia is a rich source of minerals, essential amino acids, and vitamins, and is high in antioxidants, making it a promising candidate for the management of non-communicable diseases. The potential health-promoting effects of Opuntia consumption remain relatively unexplored, and further research human trials are required to unravel its mechanisms of action.