Volleyball is a high-intensity sport that demands exceptional core strength, flexibility, explosive power, and dynamic stability, particularly among female athletes who face unique biomechanical demands and higher injury risks. This study aimed to evaluate the effectiveness of an 8-week Pilates mat exercise program as a supplementary training intervention to enhance key physical fitness components in female volleyball athletes. A randomized controlled trial was conducted with 40 young female volleyball athletes (age 18–24 years). Participants were randomly assigned to either an experimental group (n = 20) that performed Pilates mat exercises three times per week for 8 weeks in addition to regular volleyball training, or a control group (n = 20) that continued with standard training only. Pre- and post-intervention assessments included the sit-and-reach test for flexibility, half sit-up test for core endurance, vertical jump and standing broad jump for lower-body power, and functional movement screenings for stability and injury risk. Results revealed significant improvements in the Pilates group compared to the control: hamstring flexibility increased markedly (p < 0.05), core endurance improved as measured by half sit-up performance (p < 0.01), explosive power showed moderate gains, and knee functional movement patterns exhibited reduced errors in landing mechanics (p < 0.001). No significant changes occurred in the control group for most variables. In conclusion, an 8-week Pilates mat program effectively enhances flexibility, core strength, and movement quality in female volleyball athletes. These findings support the integration of Pilates as a low-impact, complementary training tool to optimize physical fitness and potentially reduce injury risk in this population.