<p>This study examines the flexural performance and damage evolution in multiscale graphene nanoplatelet-reinforced fiber metal laminates (FMLs). A multiscale modeling framework was developed to analyze the material’s mechanical response. At the mesoscale, a periodic representative volume element (RVE) approach was applied to carbon fiber/epoxy hybrid regions, enabling the calculation of homogenized mechanical properties for these composite layers. At the macroscale, simulations replicated the FMLs’ layered architecture through a unified framework integrating three material behavior laws: the Johnson-Cook model to describe aluminum sheet plasticity and damage, the three-dimensional Hashin criterion to predict failure in carbon fiber/epoxy layers, and a cohesive zone model to simulate interfacial debonding between the metal and composite phases. Experimental investigations employed quasi-static three-point bending tests to evaluate deformation and failure mechanisms in autoclave-processed FMLs reinforced with graphene. Finite element simulations corroborated experimental observations, elucidating stress distribution and progressive damage across material layers through force-displacement curves and damage propagation maps. Microscopic analysis via scanning electron microscopy (SEM) further revealed the role of graphene nanoplatelets in enhancing resin-aluminum interfacial adhesion and mitigating delamination. The proposed method is also applicable to the modification of FMLs using other types of nanofillers.</p>