SEAWEEDS are an indispensable natural source of bioactive metabolites characterized by multifunctional biomedical and pharmaceutical applications. For instance, seaweed-derived polyphenolics are potentially distinguished by their pivotal antioxidant effects in the treatment and/or prevention of several diseases. Moreover, pigments, fatty acids, terpenes, and terpenoids have been characterized by their potent antioxidant, anti-inflammatory, and antiobesity
properties, besides their highly effective hepatoprotective activities. Several seaweed-extracted polysaccharides, such as alginates, ulvans, and carrageenans, have been reported to exert various medicinal effects such as immunoinflammatory, antioxidant, antitumor, antiviral, and anticoagulant activities. Furthermore, seaweed-derived minerals have been widely utilized as food supplements and cosmeceuticals. This review discusses and emphasizes the biomedical and pharmaceutical applications of seaweeds and the future perspectives for their large-scale applications to develop novel, safe, and high-valued pharmaceutical constituents.