The thermal performance of a polymer nanocomposite is strongly influenced by the efficiency of heat transfer across the filler-matrix interface. In graphene-reinforced epoxy systems, the Thermal Boundary Resistance (TBR) represents a major limitation to the effective exploitation of graphene’s exceptional intrinsic thermal conductivity. Understanding the mechanisms governing interfacial heat transfer is therefore essential for the design of advanced thermal management materials. In the present work, the influence of the graphene oxidation on thermal transport across graphene-epoxy interfaces is investigated through Molecular Dynamics simulations. Both hydroxyl (OH) and carboxyl (COOH) functional groups are considered separately at different oxidation degrees, using pristine graphene as a reference system.