: - Participants with diagnosis of COVID-19 via an approved or authorized molecular test - Presence of symptoms compatible with COVID-19 at the time of screening - Time between onset of symptoms and first dose of hydroxychloroquine or placebo is 96 hours or less - Female participants must use an acceptable birth control method, as specified by each site and country

• COVID-19 disease requiring the use of supplemental oxygen - Electrocardiogram (ECG) tracing with QTc interval > 450 ms for men, > 470 ms for women (Fridericia algorithm recommended) - Bradycardia (< 50 beats/min) - History of cardiac disease (eg. congestive heart failure, myocardial infarction) - History of Glucose-6-phosphate dehydrogenase (G6PD) deficiency - Women who are pregnant or breastfeeding - Concurrent antimicrobial therapy - Known hypersensitivity to hydroxychloroquine or other 4-aminoquinoline compounds - Hydroxychloroquine use within 2 months before enrollment - History of severe skin reactions such as Sevens-Johnson syndrome and toxic epidermal necrolysis - History of retinopathy - History of arrythmia, concurrent use of anti-arrhythmic drugs, or family history of sudden cardiac death - History of severe renal disease (treatment with dialysis or phosphate binders) or hepatic impairment The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.