In the absence of definitive therapy for coronavirus disease (COVID-19), convalescent plasma therapy (CPT) may be a critical therapeutic option. This review was conducted to evaluate the impact of CPT in COVID-19 patients based on the publications reported to date. A robust screening of electronic databases was conducted up to 10th July 2020. Randomized controlled trials (RCTs), cohort studies, and case series with a control group evaluating the effectiveness and safety of CPT in patients with COVID-19 are included for the meta-analyses. Our search retrieved seven studies, including two RCTs and five cohort studies, with a total of 5444 patients. In patients with COVID-19, the use of CPT reduces mortality (odd's ratio [OR] 0.44; 95% CI, 0.25-0.77), increases viral clearance (OR, 11.29; 95% CI, 4.9-25.9) and improves clinically (OR, 2.06; 95% CI, 0.8 to 4.9). However, the evidence is of low quality (mortality reduction, and viral clearance), and very low quality (clinical improvement). CPT may be beneficial for reducing mortality, viral shedding and improving clinical conditions in COVID-19 patients. However, further randomized control trials (RCT) are required to substantiate the safety margin, initiation, optimal dosage, titre and duration of CPT.