Hydrogen embrittlement is a severe degradation mechanism that limits the safe use of metallic materials in the hydrogen industry. This process involves the coupling of hydrogen diffusion, thermal transport, and mechanical damage, posing significant challenges for the numerical modeling of hydrogen-assisted fractures. In practical applications such as hydrogen storage vessels, pipelines, and fuel cell systems, metallic components are commonly exposed to complex thermo–hydrogen–mechanical coupling conditions, under which hydrogen embrittlement is further aggravated. A significant number of existing studies are formulated within local continuum frameworks or involve only partially coupled multi-physics fields, which limits their capability to describe crack initiation and complex crack evolution under extreme conditions. In this work, a coupled thermo–hydrogen–mechanical peridynamic (PD) model is developed to investigate the mechanical response and fracture behavior of metals subjected to hydrogen diffusion. The temperature-dependent hydrogen diffusion and heat conduction equation are reformulated in a nonlocal form using the peridynamic differential operator (PDDO), enabling a unified transport process within the PD framework. The mechanical response is modeled using a bond-based peridynamic formulation with a bond damage criterion accounting for hydrogen embrittlement. A staggered explicit–implicit solution strategy is adopted, in which the hydrogen diffusion and thermal transport are both solved explicitly, while the mechanical response is treated implicitly to enhance numerical stability during damage and fracture evolution. Numerical examples demonstrate that the proposed model can effectively capture the coupled evolution of hydrogen diffusion, thermal transport, and material fracture, thereby providing stable and physically consistent predictions of the crack initiation and propagation. The proposed framework offers an efficient nonlocal computational approach for simulating hydrogen embrittlement in metallic materials.