This study proposes a sustainable optimization model for a multi-echelon fish supply chain incorporating waste recycling. The proposed model integrates forward and reverse logistics to minimize total costs, including transportation, fuel, product processing, waste processing, and inventory holding costs. The supply chain consists of 24 fish farms, a slaughterhouse, primary and secondary processing plants, wholesalers, retailers, and a waste recycling center. Numerical examples demonstrate the model’s effectiveness, and sensitivity analysis reveals the impact of variations in processing and holding costs on total costs. The results underscore the significance of optimizing processing costs for substantial cost savings. Future research can look into incorporating carbon emissions and additional stakeholders to enhance decision-making and policy development.