Carbon Dots (CDs) are the latest addition in the carbon nanostructures family. In general, CDs structure consists of a carbon core and a large number of functional groups (− OH, − COOH, − NH 2 , etc.) on the surface. Due to their unique properties, including small size, photoluminescence, photostability, biocompatibility and low toxicity, CDs could be employed for sensing, photocatalysis, bioimaging, optoelectronic and energy storage applications. In addition, the abundant functional groups on their surface could operate as active coordination sites for interactions with other nanomaterials, producing a large number of CDs-based hybrid materials, including CDs/2-D hybrid materials. This critical review discusses the scientific work published in the literature during the last five years, referring to the combination of CDs with 2-D nanomaterials (graphene-based materials, g-C 3 N 4 , TMDCs, LTMOs, LDHs and LDOs), the effects of CDs in 2-D properties and their potential applications in a wide range of scientific/technological areas. [Display omitted] [ABSTRACT FROM AUTHOR]