For individuals with Down syndrome (DS), obstructive sleep apnea (OSA) is a complex disorder with significant clinical consequences. OSA is seen frequently in DS, and when present, it tends to be more severe. This increased prevalence is likely related to common anatomic abnormalities and a greater risk of additional comorbidities such as hypotonia and obesity. Because signs and symptoms do not often correlate with disease, all children and adults with DS should receive routine screening for OSA. Similar to the general population, polysomnography remains the gold standard for diagnosis. Because individuals with DS may be more susceptible to cardiovascular and neurocognitive sequelae, early diagnosis and treatment of OSA is becoming increasingly important. Treatment options generally involve upper airway surgery (primarily adenotonsillectomy) and continuous positive airway pressure (CPAP); however, various adjunctive therapies including intranasal steroids, palatal expansion, and oropharyngeal exercises are also available. Residual disease status post adenotonsillectomy is common, and further evaluation (eg, drug-induced sleep endoscopy [DISE]) is often needed. More advanced and directed airway surgery can be performed if additional sites of obstruction are observed. Novel therapies including hypoglossal nerve stimulation are emerging as effective treatments for refractory OSA. Due to the diversity among individuals with DS, personalized treatment plans should be developed. Within this arena, opportunities for research remain abundant and should include areas involving patient risk factors, alternative diagnostic methods, and outcome analysis.