Products derived from marine resources, including seafood and bioactive and pharmaceutical compounds, play a significant role in promoting health and advancing the development of novel therapies. Epidemiological evidence indicates that marine-based dietary patterns are associated with a reduced prevalence of chronic non-communicable diseases, including cardiovascular diseases, type 2 diabetes, and certain cancers—an effect largely attributed to their high content of omega-3 fatty acids, antioxidants, and essential micronutrients. These compounds exert their effects through the reduction of inflammation, regulation of metabolism, improvement of endothelial function, and attenuation of oxidative stress. In addition, marine resources constitute a rich reservoir of bioactive compounds with anticancer, anti-inflammatory, antiviral, and immunomodulatory potential, some of which have already reached clinical application. Despite this considerable potential, environmental, technical, and regulatory challenges constrain the sustainable exploitation of these resources. Overall, this review underscores the strategic importance of marine-derived food products and bioactive compounds in disease prevention and the development of next-generation therapeutics.