Buckminsterfullerene (C60), known for its strong radical scavenging properties, has been studied extensively for its biomedical applications. Its clinical use would be promoted by novel functionalization of C60 with the aid of drug delivery carriers based on nanoparticle technologies. Cellulose nanocrystals (CNCs) have recently been exploited as a promising nanoplatform for drug delivery, owing to their intriguing attributes such as nanoscale dimensions, low toxicity, broad chemical-modifying capacity, and biocompatibility. Herein, cellulose nanocrystals carrying buckminsterfullerene (CNC-C60) have been synthesized via amine functionalization of CNCs and subsequent grafting of C60 onto the surface of amine-terminated CNCs. FTIR and XPS measurements confirmed the success of the synthesis, which was further evidently supported by TGA analysis. Given atomic compositions of samples by elemental analysis, we figured out a C60 content of 0.17 mmol/g of CNC-C60, equivalent to 34 C60 molecules/1000 anhydroglucose units (AGU). Afterward, CNC-C60 was evaluated for its antiradical effects on scavenging hydroxyl radicals in vitro. The ease of synthesis and significant radical scavenging activity make CNC-C60 a promising novel antioxidant agent for biomedical use.