Graphene has emerged as a novel green broad-spectrum antibacterial material, with little bacterial resistance and tolerable cytotoxic effect on mammalian cells. It exerts its antibacterial action via physical damages such as direct contact of its sharp edges with bacterial membranes and destructive extraction of lipid molecules. These damages also include wrapping and photothermal ablation mechanisms. Alternatively, chemical damage of bacteria is caused by oxidative stress with the generation of reactive oxygen species and charge transfer. Furthermore, graphene has been used as a support to disperse and stabilize various nanomaterials, such as metals, metal oxides, and polymers, with high antibacterial efficiency due to the synergistic effect. In addition, graphene-based antibiotic drug delivery platforms have been constructed. Due to the superior antibacterial properties and good biocompatibility, graphene-based nanocomposites have a wide range of applications, such as antibacterial packaging, wound dressing, and water disinfection. In this review, we highlight the antibacterial mechanism of graphene and summarize recent advances related to the antibacterial activity of graphene-based materials. Many of the recent application examples are further discussed. We hope that this review provides valuable insight, stimulates broader concerns, and spurs further developments in this promising field.