Hydrogen offers a compelling solution to the energy challenges of supply, security, pollution, and climate change. Although today’s technology enables several routes for producing, storing, and using hydrogen, none of them are yet competitive with fossil fuels for cost, performance, or reliability. Dramatic advances in the basic understanding of hydrogen and its interactions with materials are needed to bring a hydrogen economy to practical realization. The current state of hydrogen technology and the research challenges for creating a mature hydrogen economy will be discussed.