AbstractThe assembly of carbon nanomaterials into three‐dimensional (3D) porous scaffolds is critical to harness their unique physiochemical properties for tissue engineering and regenerative medicine applications. In this study, we report the fabrication, characterization, and in vitro cytocompatibility of true 3D (>1 mm in all three dimensions), macroscopic (3–8 mm in height and 4–6 mm in diameter), chemically cross‐linked graphene scaffolds prepared via radical initiated thermal cross‐linking of single‐ and multiwalled graphene oxide nanoribbons (SWGONRs and MWGONRs). SWGONR and MWGONR scaffolds possess tunable porosity (∼65‐80%) and interconnected macro‐, micro‐, and nanoscale pores. Human adipose derived stem cells (ADSCs) and murine MC3T3 preosteoblast cells show good cell viability on SWGONR and MWGONR scaffolds after 1, 3, and 5 days comparable to 3D poly(lactic‐co‐glycolic) acid (PLGA) scaffolds. Confocal live‐cell imaging showed that cells were metabolically active and could spread on SWGONR and MWGONR scaffolds. Immunofluorescence imaging showed the presence of focal adhesion protein vinculin and expression of cell proliferation marker Ki‐67 suggesting that cells could attach and proliferate on SWGONR and MWGONR scaffolds. These results indicate that cross‐linked SWGONR and MWGONR scaffolds are cytocompatible and opens‐avenues toward the development of 3D multifunctional graphene scaffolds for tissue engineering applications. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 73–83, 2017.