<p>The valorisation of fish waste (FW) presents a promising avenue for sustainable resource utilization and economic value creation. In this regard, this paper conducted a technoeconomic investigation into alternative technologies for the valorisation of FW. Various technologies, including subcritical water hydrolysis, enzymatic hydrolysis, and anaerobic digestion, were considered in the analysis. Through economic modelling and sensitivity analyses using ASPEN Plus software, the feasibility and economic viability of different valorisation strategies, designated as scenarios (a), (b), and (c) for the production of protein hydrolysate powder, electricity, protein hydrolysate powder, fatty acids, and electricity only, respectively, were assessed. The results revealed that utilizing subcritical water technology in scenario (b) yields the most economically viable strategy, with its positive Net Present Value (NPVs) of US$31.86 million indicating economic feasibility. Conversely, the NPVs of scenarios (a) and (c) of -US$25.05 million and of -US$12.09 million respectively demonstrated economic infeasibility. Additional analyses of economic viability showed the influence of processing capacities and operating costs on economic feasibility. Furthermore, environmental performance evaluations based on CO₂ equivalent metrics revealed some correlation between profitability and environmental outcomes, highlighting the lack of decision conflicts when identifying the optimal valorisation pathway in the present study. Despite modelling challenges and uncertainties, the study highlights the potential for sustainable and economically viable utilization of FW, offering valuable insights for decision-makers in the seafood industry.</p> Graphical Abstract <p></p>