Neutron-based metrologies are particularly well-suited for studying materials of relevance to fuel-cell technologies. Novel neutron properties such as the nuclear nature of the neutron-matter interaction, the unusually large scattering cross section for hydrogen (and deuterium), and great penetrating power render the neutron a unique and invaluable probe of the amount, location, bonding states, and dynamics of hydrogen (and water) in a wide range of hydrogen-related materials. Developments over the past decade at the NIST Center for Neutron Research and elsewhere have greatly increased the sensitivity and dynamic range of neutron instrumentation, enhancing its versatility for fundamental materials characterization. In this presentation, an overview of the capabilities of such modern neutron instrumentation for the study of fuel-cell systems and materials will be presented, from micron-scale imaging of water management in working fuel-cell stacks to atomic-scale characterization of the nature and behavior of hydrogen and water within fuel-cell membranes.