Extremely halophilic archaea inhabit hypersaline environments and have evolved unique metabolic strategies to withstand osmotic and oxidative stress. This chapter highlights their potential as sustainable platforms for bio-based production. Recent advances in carotenoid biosynthesis are summarized, including novel bifunctional enzymes that expand current knowledge of archaeal metabolism. The physiological and biomedical roles of carotenoids, such as antioxidant and anticancer activities, are discussed alongside strategies for enhancing production in native and engineered hosts. In addition, other valuable products, including retinal proteins, biopolymers, biosurfactants, and halocins, are explored as emerging applications.