Perioperative sleep disorders are common and associated with multiple adverse events. Promoting perioperative sleep may help improve postoperative recovery. Dexmedetomidine is a highly selective α2 adrenergic agonist with anxiolytic, sedative, and analgesic effects. This review summarized the effects of dexmedetomidine on perioperative sleep. Recent studies suggest that perioperative use of dexmedetomidine not only improves sleep structure and subjective sleep quality, but also increases bradycardia and hypotension. Intravenous administration of low‑dose dexmedetomidine or trans‑nasal administration of sedative dose dexmedetomidine may also improve perioperative sleep quality while decrease adverse events. Administration of dexmedetomidine‑esketamine combination may produce a synergistic effect in improving perioperative sleep quality with less neuropsychiatric symptoms. The impact of dexmedetomidine in improving perioperative sleep and on clinical outcomes deserves further exploration.