This editorial outlines the evolving role of thermo-fluid sciences in advancing sustainable energy systems amid the global energy transition. It highlights key research frontiers, including decarbonization of thermal power and propulsion, next-generation renewable thermal technologies, advanced thermal management and energy storage, innovative working fluids, and the integration of AI/ML with high-fidelity simulations. The journal calls for interdisciplinary, multi-scale studies that link fundamental thermo-fluid advances to system-level sustainability impacts, such as exergy efficiency, life-cycle emissions, and grid resilience. IJTFSSE aims to serve as a leading platform for rigorous resea... More >