Background <p>Children with cerebral palsy (CP) may face challenges when engaging in activities that require simultaneous cognitive and motor efforts. Repetitive transcranial magnetic stimulation (rTMS) has the potential to improve motor and cognitive functions in some populations. However, the effect of rTMS on the performance of cognitive-motor dual-task in children with CP remains unclear.</p> Objective <p>To investigate the efficacy and safety of rTMS on the performance of cognitive-motor dual-task in children with CP.</p> Methods <p>In this randomized controlled trial, forty-four children with CP (aged 6–12 years) were recruited. They were randomly allocated to receive 3 consecutive sessions of active or sham rTMS applied to the left dorsolateral prefrontal cortex (DLPFC). Participants were asked to perform the Box and Block Test (BBT) and Serial Subtraction Test (SST) separately or simultaneously before and immediately after each rTMS session.</p> Results <p>Forty participants completed the study (22 in the active rTMS group). On day 3, significant enhancements were observed in SST scores for the active rTMS group compared to the sham group (single-task:14.4 ± 1.6 vs. 8.89 ± 1.8, <i>p</i> = 0.024; dual-task: 9.36 ± 1.0 vs. 3.89 ± 1.1, <i>p</i> = 0.001). Under the dual-task condition, the active rTMS group displayed a greater improvement in BBT scores than the sham group on day 3 (8.91 ± 1.03 vs. 3.83 ± 1.14, corrected <i>p</i> = 0.003). There were no notable differences between the two groups in the improvement of BBT scores under the single-task condition. No serious adverse events were reported.</p> Conclusion <p>The rTMS applied to the left DLPFC is safe and effective in improving the performance of cognitive-motor dual-task in children with CP.</p>