The hydrogen economy promises environmentally clean fuel cell power based on abundant and sustainable energy resources. Hydrogen storage has been identified as a bottleneck of the hydrogen economy. My research focuses on novel multi-principal element alloys (MPEAs) for hydrogen storage. MPEA hydrides (MPEA-H) have recently indicated new and promising possibilities for satisfying the delicate trade-off between sufficiently high hydrogen storage capacity, appropriate thermodynamics for reversible hydrogenation near room temperature, and fast kinetics. However, the tunability of MPEAs presents an intractably large design space for traditional “trial and error” approaches. Further, little is known about what factors control the intrinsic thermodynamics and kinetics of the MPEA-hydrogen reaction, and structure and properties of the alloy and hydride phases involved. Here, I employ machine learning, computational thermodynamics, and quantum-mechanical calculations to (1) high-throughput screen the MPEA design space for compositions with desired hydrogenation thermodynamics and phase constitution; (2) model para-equilibrium of the MPEA-hydrogen system, predict pressure-composition-temperature diagrams and hydrogenation pathways; (3) provide mechanistic understanding of hydrogen diffusion in MPEA-H. My research will result in knowledge that facilitates the selection of promising MPEAs for hydrogen storage from a large library, subjected to characterization at experimental partners.