This book provides a comprehensive overview of recent developments to valorize fish waste as a source of useful products. In the first few chapters, an introductory section unearths global fish waste production, its detrimental effects and its role in the circular economy. The next section of the book discusses recent applications of fish waste and by-products utilization for the production of useful products such as fertilizers, biogas, biodiesel, fish sauce, enzymes and many more. This book will serve as an important source of recent research developments and applications of fish waste generated at different stages of fish processing. This book will also act as an important reference to the research group conducting research on fish and fish by-product utilization and valorization.