Understanding thermodynamic and kinetic behavior of hydrogen in Ti is key for preventing and improving corrosive and functional roles, respectively, of hydrogen for structural and energy storage applications. However, knowledge gaps remain due to the complexity of the associated mechanisms incorporating multiscale/multiphysics nature. Specifically, these involve coupled interfacial phenomena, including surface reaction, mass transport, structural transformation, and phase evolution. Therefore, several experimental and modeling approaches are needed to explore various facets of titanium hydrogenation mechanisms. This presentation will report our recent progress in investigating hydrogenation behavior in Ti using the combined modeling-experimental approaches. Particularly, we will discuss how multiscale/multiphysics factors are integrated for describing hydrogen interactions in polycrystalline Ti. We will then show how experimental characterizations and modeling are combined to analyze hydrogen-Ti interactions, focusing on key chemical and physical phenomena: surface reaction selectivity, hydrogen transport through surface oxide and grain boundaries, hydride nucleation-and-growth, and thermal transport through metal-hydride microstructures.