<p>Fish processing industries generate large quantities of by-products, including heads, skin, bones and viscera, which are often underutilized and contribute to environmental pollution. Among these wastes, fish viscera are a promising source of proteolytic enzymes with significant industrial potential. Fish-derived proteases exhibit desirable properties such as high catalytic activity, functionality at low temperatures and stability over a wide range of pH conditions, making them suitable for applications in food processing, detergents, leather treatment, pharmaceuticals and waste management. This review critically examines the potential of fish visceral waste as a sustainable source of industrial proteases, with emphasis on enzyme sources, recovery approaches, purification strategies, biochemical characteristics and industrial applications. The review further discusses the advantages of utilizing fish visceral proteases over conventional microbial enzymes, particularly in terms of sustainability, waste valorisation and circular bioeconomy development. In addition, current limitations and challenges associated with enzyme extraction, stability and large-scale commercialization are highlighted. By integrating recent advancements in the field, this review highlights the effective utilization of fish processing waste and emphasizes the potential of fish visceral proteases as eco-friendly biocatalysts for sustainable industrial applications.</p>