Graphitic carbon nitride, (g-C₃N₄), is a polymeric derived carbon-nitrogen molecule, and its derivatives have found extensive application in biomedicine. Synthetic g-C₃N₄ nanoparticles (GCN-Np) stands out for their anti-cancer activity attributed to their conductivity, strength, chemical and thermal endurance. Here, we investigate the potential mechanism action and efficacy of GCN-Np in glioblastoma cells. The mechanically synthesized g-C3N4 was structurally characterized using Field emission scanning electron microscopy, Fourier transform infrared spectroscopy, UV-Spectroscopy, and X-ray diffraction techniques. The findings revealed that the GCN-Np displayed C=N stretching, C–N, -NH- and -NH₂ functional groups attributed to the graphitic carbon compounds with an average particle size of 300 nm. Cell death analysis indicated that the IC50 concentrations of GCN-Np and TMZ are 4.7 μg/mL and 9.3 μg/mL for LN229, and 15.9961 μg/mL and 16.8 μg/mL for SNB19 GBM cells, respectively. GCN-Np effectively arrested the cell cycle at S phase approximately <50 %, in both GBM cells, thereby preventing the possibility of cell division prior to DNA synthesis. FACS analysis validated the role of GCN-Np and TMZ in eliciting ROS-mediated apoptosis at around 91 % and 93 %, respectively. Finally, the ability of GCN-Np to prevent the migration of GBM cells was observed to be significantly higher than the TMZ. In non-cancerous cells, MEF, GCN-Np demonstrates minimal cytotoxicity, confirming its selective targeting of malignant cells. Overall, the GCN nanoparticles exhibited promising anti-GBM effects with minimal cytotoxicity to non-cancerous MEF cells, suggesting their potential for further therapeutic investigations.