At present, graphene has been widely utilized in electronics, electric devices, and biosensors. As its unparalleled properties including high surface area, excellent conductivity, ease of functionalization, and production, graphene provides an ideal platform to make useful nanomaterials, and motivates researchers to synthesize metallic nanoparticles–graphene nanocomposites for fabricating of sensors and biosensors. Fabrication of metallic nanoparticle–graphene nanohybrids and their application in sensing systems allows greatly sensitive, selective, stable, and fast electrochemical sensing of analytes. This review presents the recent studies in the construction of metallic nanoparticles graphene or graphene oxide composite-based electrochemical biosensors. It discusses the application of metallic nanomaterials to the assembly of graphene- and graphene oxide-based electrochemical enzymatic biosensors and its analytical performance.