Graphene-based nanomaterials are promising in a wide range of applications due to their unique structural, chemical and physical properties that have recently led to their investigations as co-catalysts and nanoparticle catalyst templates for organic, electrochemical and photochemical reactions. Herein, we present an overview of hybrid metal nanoparticle-graphene catalysts with specific attention to the most recent achievements since 2015. The state-of-the-art of their synthesis and characterization is also summarized, and the synergistic metallic nanoparticle-graphene interactions and their functions in catalysis are discussed. Finally, challenges and future outlooks for this hot area are envisaged. (C) 2018 Elsevier Ltd. All rights reserved.