<p>Macroalgae presents a transformative and sustainable solution to critical environmental challenges, particularly in lignocellulosic biomass valorization, phycoremediation, carbon sequestration, and the production of high-value products. Due to their high polysaccharide content and low lignin levels, macroalgae are ideal for biofuel production, generating biogas and biodiesel, and offer promising potential for bioplastics, supporting sustainable practices. Through biosorption and bioaccumulation, they efficiently remove heavy metals, excess nutrients, and organic pollutants from wastewater, positioning them as a powerful tool for environmental remediation and a renewable industry resource. Cost-effective cultivation systems, especially in shallow ponds, allow natural wastewater treatment without mechanical aeration, amplifying their ecological impact. Additionally, macroalgae's rich bioactive compounds make them invaluable in food, pharmaceuticals, nutraceuticals, and animal feed industries, enhancing economic sustainability. As a renewable resource, macroalgae produce diverse products—biofuels, biochar, glycerol, pigments, nutraceuticals, and pharmaceuticals—that drive environmental sustainability while empowering communities, particularly women in coastal areas, fostering entrepreneurship in green industries. By addressing ecological challenges and opening economic avenues, macroalgae contribute significantly to achieving the United Nations Sustainable Development Goals (SDGs), advancing food security, climate action, biodiversity conservation, sustainable livelihoods, and social equity.</p> Graphical Abstract <p></p>