A systematic review and meta-analysis of three randomized controlled trials evaluated the effects of melatonin supplementation (3–6 mg/day) versus placebo on sleep quality and severity of atopic dermatitis in children. Melatonin significantly reduced sleep onset latency with a pooled standard mean difference of −0.63 (95% CI: −1.00 to −0.26, p = 0.0009). The mean difference in mean SCORAD disease severity improved by −6.60 (95% CI: −10.11 to −3.10, p = 0.0002), although overall SCORAD was nonsignificant and did not include minimal clinically important changes. It had no significant effect on IgE levels (SMD = -0.19, 95% CI: -0.46 to 0.09, p = 0.18) or total sleep duration (mean difference = 18.29 min, 95% CI: -10.31 to 46.82, p = 0.81). The heterogeneity of the results was minimal (I2 = 0–4%). No adverse events were reported.