Purpose <p>Sleep disturbances are frequent among children with severe cerebral palsy, leading to huge burden on caregivers. This study aimed to evaluate the efficacy and safety of suvorexant for treating sleep disorders in children.</p> Methods <p>Sixteen patients, aged 2–16, with sleep disorders were administered with suvorexant. Patient characteristics, efficacy, and safety of suvorexant were retrospectively investigated from patients’ charts, and the Athens Insomnia Scale (AIS) scores surveyed by caregivers were compared before and after administering suvorexant.</p> Results <p>Suvorexant was effective in 13 of 16 patients (81%). Multiple sleep disturbance patterns were observed in all patients. Suvorexant was effective in 81% (<i>n</i> = 13/16) of sleep maintenance disorders, 77% (<i>n</i> = 10/13) of sleep onset disorders, 100% (<i>n</i> = 9/9) of early awakening disorders, and 91% (<i>n</i> = 10/11) of circadian rhythm sleep-wake disorders. The mean maintenance dose in effective cases was 0.3&#xa0;mg/kg (IQR, 0.28–0.42). AIS scores revealed a significant decrease in all items and total scores, which decreased from a mean of 15.0 to 4.7. No major adverse events were observed.</p> Conclusions <p>Our results suggest that suvorexant is safe and provides sufficient improvement in insomnia and circadian rhythm disorders in children with severe cerebral palsy, leading to improved quality of life.</p>