In recent years, nano-engineered fibre-reinforced composites (FRC) often called multi-scale composites have received great attention due to their enhanced high performance. Nanofillers such as graphene nanoplatelets (GNPs) or carbon nanotubes (CNTs) can be deposited on carbon fibres by different strategies, creating so-called hierarchical fibres. Hierarchical fibres reinforce the interphase between fibre and matrix and improve the mechanical and electrical properties of FRC, such as interlaminar shear strength, flexural properties and structural health monitoring capabilities. Modelling the mechanical behaviour of this complex nano-engineered material remains challenging. The Finite Element Method (FEM) requires simulations at multiple scales i.e., nano, micro and macroscale.[1]. However, one of the main difficulties in FEM is the accurate implementation of material properties in the model. It becomes even more complicated to study hierarchical fibres, where the properties of nano-reinforced interphase are not available. For traditional FRC, it is commonly accepted that the interphase properties are somewhere between those of fibre and matrix. Recently, some attempts to map the mechanical properties of hierarchical fibres were made [2]. This research presents an optimisation method to predict the interphase properties of nano-engineered FRC inversely, which combines both macro and microscale FEA simulations. The optimisation process was performed using ANSYS DesignXplorer. Validation of this method was conducted using a three-phase RVE model to compare with published results. Various optimisation algorithms, i.e. screening, multi-objective and adaptive multi-objective were tested and compared to evaluate their effectiveness and accuracy during the optimisation process. These two steps in this optimisation procedure were uncoupled but connected via the properties of the lamina. The optimisation was performed to determine the properties of the interphase. The homogenised GNPs nano-reinforced interphase’s properties were inversely characterised. The effects of the parameters, such as interphase thickness and orientation of the GNPs, were discussed.