Background: Poly methylmethacrylate (PMMA) resin, commonly known as acrylic resin, is a standard material for denture base construction, yet challenges persist in balancing natural aesthetics with durability. This study compares the flexural strength of heat cure acrylic resin reinforced with zinc oxide nanoparticles and E-glass fiber, aiming to enhance denture longevity and resilience. Method: A total of 30 specimens of DPI Heat Cure, India, were classified as Group A without reinforcement, Group B reinforced with 1.4% Zinc oxide nanoparticles, and Group C reinforced with E-glass fiber. The fabrication process included mixing the resin, packing, and polymerization and finishing. ANOVA tests were used for statistical analysis. Results: Flexural strength testing was performed using a Universal Testing Machine, with results indicating significant differences among the groups. The mean flexural strengths were: ZnOE Nanoparticle group 93.34 MPa, E-glass fiber group 81.59 MPa, and Heat Cure acrylic resin group 59.54 MPa. Statistical analysis confirmed the ZnOE Nanoparticle group showed the highest flexural strength, followed by the E-glass fiber group, and the heat-cure acrylic resin group exhibited the lowest. Conclusion: Reinforcement with ZnOE Nanoparticles significantly improved the flexural strength of heat-cure acrylic denture base specimens compared to E-glass fiber and Heat Cure acrylic resin. E-glass fiber also demonstrated significantly higher strength than heat-cure acrylic resin. These findings underscore the importance of material selection in denture base construction for enhanced durability.