Vitamin D supplementation may have beneficial effects on cardiovascular outcomes in patients with chronic kidney disease (CKD), but the underlying data are conflicting. We conducted a meta-analysis to investigate the effect of vitamin D on cardiovascular outcomes in patients with CKD. We searched MEDLINE (via PubMed), the Cochrane Library, Scopus, and ClinicalTrials.gov from inception to 16 March 2024 for all randomized controlled trials (RCTs) assessing vitamin D supplementation in patients with CKD and reporting cardiovascular outcomes. Our primary outcomes were the incidence of adverse cardiovascular events and the change in left ventricular ejection fraction (LVEF) and left ventricular mass index (LVMI). Our secondary outcomes were the change in systolic blood pressure (SBP) and diastolic blood pressure (DBP). Data were pooled using risk ratio (RR) and mean difference as the effect measures. A total of 11 RCTs were included in our review. Vitamin D supplementation reduced the risk of adverse cardiovascular events in patients with CKD (RR 0.39; 95% CI 0.22 to 0.69; I2=0). There was no significant difference in LVEF, LVMI, SBP, and DBP between the vitamin D and control groups. Vitamin D supplementation does not affect adverse cardiovascular events, LVEF, LVMI, SBP, and DBP. Further large-scale RCTs and mechanistic studies are needed to understand the potential benefits of vitamin D supplementation in this patient population.