Graphene has been extensively explored to enhance functional and mechanical properties of metal matrix nano-composites for wide-range applications due to their superior mechanical, electrical and thermal properties. This article discusses recent advances of key mechanisms, synthesis, manufacture, modelling and applications of graphene metal matrix nanocomposites. The main strengthening mechanisms include load transfer, Orowan cycle, thermal mismatch, and refinement strengthening. Synthesis technologies are discussed including some conventional methods (such as liquid metallurgy, powder metallurgy, thermal spraying and deposition technol-ogy) and some advanced processing methods (such as molecular-level mixing and friction stir processing). Analytical modelling (including phenomenological models, semi-empirical models, homogenization models, and self-consistent model) and numerical simulations (includingfinite elements method,finite difference method, and boundary element method) have been discussed for understanding the interface bonding and per-formance characteristics between graphene and different metal matrices (Al, Cu, Mg, Ni). Key challenges in ap-plying graphene as a reinforcing component for the metal matrix composites and the potential solutions as well as prospectives of future development and opportunities are highlighted.