Hydrogen is gaining significance in the worldwide transition to renewable energy sources, but the technologies used to produce it currently are mostly carbon-intensive and unsustainable. The current developments in environmentally friendly hydrogen generation by electrochemical and photoelectrochemical water splitting with readily available earth-based catalysts are the main topic of this plenary discussion. We will explore the development and application of innovative, cost-effective catalysts derived from earth-abundant elements such as iron, nickel, and cobalt, which show promising performance in both processes, potentially surpassing the efficiency of precious metal-based catalysts while significantly reducing production costs. The presentation will cover the current state of hydrogen production and its environmental impact, the principles of electrochemical and photoelectrochemical water splitting, design strategies for high-activity and stable earth-abundant catalysts, recent breakthroughs in catalyst materials and nanostructures, performance comparisons between earth-abundant and precious metal catalysts, as well as challenges and opportunities in scaling up these technologies. By highlighting these cutting-edge developments, this talk aims to demonstrate the viability of earth-abundant catalysts in advancing sustainable hydrogen production, establishing the way for a cleaner and more economically feasible hydrogen-based energy future.