The global steel sector faces a crucial turning point as it grapples with the twin challenges of meeting rising global demand while reducing its significant carbon footprint. This report, a collaboration between RMI and the Green Hydrogen Catapult, highlights the urgency in transforming steel supply chains towards sustainability by embracing renewable hydrogen-based ironmaking. With steel production currently responsible for 11% of global CO2 emissions, the need for a shift to greener practices is evident. The report emphasizes the potential of green iron corridors as a solution for reducing emissions, enhancing cost-effectiveness, and fostering economic growth in the steel industry. By segregating ironmaking and steelmaking processes based on resource availability and energy sources, countries can optimize their production methods and capitalize on renewable energy resources. The establishment of green iron corridors not only promises significant cost savings but also opens doors for increased efficiency and economic opportunities for both steel importers and exporters. Moreover, transitioning a substantial portion of primary steelmaking to green iron could result in annual savings exceeding $25 billion and a notable reduction of 30 million tons of CO2 emissions by 2030. The report's comprehensive assessment framework offers insights into the challenges and opportunities associated with green iron corridors, providing a roadmap for decarbonizing the steel sector in the coming decade. With the right strategies and concerted efforts, the vision of sustainable steel supply chains powered by renewable energy sources could soon become a reality.