Background Somnipathy and diabetes are independently associated with an increased risk of cardiovascular disease (CVD). However, whether a combination of both conditions is associated with a higher risk of CVD events remains uncertain. Therefore, the aim of this meta-analysis was to clarify this association. Methods and Results We searched MEDLINE, Web of Science, EMBASE, ClinicalTrials.gov, and the Cochrane Central Register for Controlled Trials. We included randomized controlled trials, nonrandomized trials, and prospective observational cohort studies that assessed the combined effect of diabetes and comorbid somnipathy on CVD risk and mortality for at least 1 year. Outcomes included CVD, coronary heart disease, stroke, and all-cause mortality. Twelve studies involving 582 267 participants were included in the meta-analysis. Patients with somnipathy and comorbid diabetes exhibited increased risks of CVD, coronary heart disease, stroke, and all-cause mortality (risk ratio [RR], 1.27 [95% CI, 1.12-1.45], <0.0001; RR, 1.40 [95% CI, 1.21-1.62], <0.0001; RR, 1.28 [95% CI, 1.08-1.52], =0.004, and RR, 1.56 [95% CI, 1.26-1.94], <0.0001, respectively). Conclusions The coexistence of somnipathy and diabetes is associated with higher risks of CVD, coronary heart disease, stroke, and mortality than somnipathy or diabetes alone. Resolving sleep problems in patients with diabetes may reduce the risks of CVD, stroke, and mortality. Registration Information https://www.crd.york.ac.uk/prospero/. Identifier: PROSPERO CRD42021274566.