The primary objective of global studies is to develop the properties and durability of polymers for various applications. When it comes to dental disability, denture base materials must have sufficient mechanical and tribological performance in order to withstand the forces experienced in the mouth. This work aims to investigate the effects of the addition of low content of cellulose nanocrystals (CNC) on the mechanical and tribological performance of the polymethyl methacrylate (PMMA) nanocomposites. Different weight percent of CNC (0, 0.2, 0.4, 0.6, and 0.8 wt%) were added to the PMMA matrix followed by ball milling to evenly distribute the nanoparticles reinforced phase in the matrix phase. The findings emphasize the significant impact of CNC integration on the performance of PMMA nanocomposites. By increasing the content of the CNC nanoparticles, the mechanical properties of PMMA were improved. In addition, the tribological outcomes demonstrated a significant reduction in the friction coefficient besides an enhancement in the wear resistance as the weight percentage of nanoparticles increased. The surface of the worn samples was investigated by utilizing SEM to identify the wear mechanisms corresponding to the different compositions. In addition, a finite elment model (FEM) was developed to ascertain the thickness of the worn layer and the generated stressed on the surfaces of the nanocomposite throughout the friction process.