This research paper presents a comprehensive investigation into the synergistic impacts of fly ash and bottom ash on the mechanical performance of geopolymer concrete. An optimization framework based on Response Surface Methodology was employed to develop quadratic models that predict the compressive and flexural strengths of the geopolymer concrete as a function of the fly ash and bottom ash replacement levels. The ANOVA results confirmed the statistical significance of the models, indicating that the fly ash content had a dominant influence on the mechanical properties, followed by the bottom ash content. The optimization analysis revealed that the optimal mix design to maximize both compressive and flexural strength is achieved with 53.79% fly ash and 51.52% bottom ash as replacement materials for cement and fine aggregates, respectively. This optimal mixture design resulted in a compressive strength of 35.93 MPa and a flexural strength of 4.82 MPa, representing an improvement of 42.58% and 33.89%, respectively, compared to the control mixture. The study provides valuable insights into the synergistic utilization of these industrial by-products in the development of high-performance and sustainable geopolymer concrete.