This quasi-experimental study evaluated the psychosocial impact of a structured FIT INDIA Movement physical activity program on self-esteem in children diagnosed with Autism Spectrum Disorder (ASD). Forty participants aged 7 to 12 years from three therapy centres in Tiruchirappalli, India, were randomly assigned to an intervention group or a waitlist control group. The intervention comprised 12 weeks of FIT INDIA–based aerobic, balance, and coordination exercises adapted for ASD. Self-esteem was measured pre- and post-intervention using the Rosenberg Self-Esteem Scale (RSES) with parent-assisted administration protocols. Intervention fidelity was monitored through therapist adherence checklists and attendance logs, and therapists experienced in ASD led the sessions. Statistical analyses included paired t-tests and repeatedmeasures ANOVA, revealing significant improvement in self-esteem for the intervention group (p < .001, Cohen’s d = 1.8). Findings underscore the potential of national fitness initiatives to enhance psychosocial health in ASD populations, and underscore the need for larger multicenter randomized trials incorporating diverse measurement approaches.