This book contains the proceedings of the 3rd IFToMM Workshop for Sustainable Development Goals (I4SDG), held in Lamezia Terme, Italy, on June 9–11, 2025. The workshop papers are focused on those aspects of the theory, design, and applications of mechanism and machine science that are fundamental for moving toward sustainable development. The main topics of the workshop are: sustainable energy systems, robotics and mechatronics, biomechanical and medical systems, education, linkages, gears, transmissions and actuators, engines and powertrains, tribology, transportation machinery, service systems for sustainability, humanitarian engineering, and socio-technical systems for sustainable and inclusive development. The contributions, selected through a rigorous international peer-review process, highlight many exciting ideas that will drive new research directions and foster multidisciplinary collaboration between researchers from different backgrounds.