Introduction: Controversy exists about an association between angiotensin-converting-enzyme inhibitors (ACEIs), angiotensin-receptor blockers (ARBs), and thiazides (TZs) and the risk of malignant melanoma (MM), and non-melanoma skin cancer—basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Objective: The aim of this study was to determine if an association exists for ACEI, ARB, or TZ exposure and skin cancers. Methods: This was a matched cohort study using a large electronic medical records repository, the Northwestern Medicine Enterprise Data Warehouse (NMEDW). The exposed population consisted of patients with a documented order for an ACEI, ARB, or TZ with no prior history of skin cancer. The control population consisted of matched patients without documented exposure to ACEI, ARB, or TZ and no previous skin cancer. Incident MM, BCC, or SCC diagnosis by ICD-9 codes was recorded. Odds ratios (ORs) were obtained by using logistic regression analyses. Results: Among the 27,134 patients exposed to an ACEI, 87 MM, 533 BCC, and 182 SCC were detected. Among the 13,818 patients exposed to an ARB, 96 MM, 283 BCC, and 106 SCC were detected. Among the 15,166 patients exposed to a TZ, 99 MM, 262 BCC, and 130 SCC were detected. Significant associations using ORs from logistic regression were found for MM and TZs (OR 1.82; 95% confidence interval [CI] 1.01–3.82); BCC and ARBs (OR 2.86; 95% CI 2.13–3.83), ACEIs (OR 2.23; 95% CI 1.78–2.81) and TZs (OR 2.11; 95% CI 1.60–2.79); SCC and ARBs (OR 2.22; 95% CI 1.37–3.61), ACEIs (OR 1.94; 95% CI 1.37–2.76), and TZs (OR 4.11; 95% CI 2.66–6.35). Conclusions: A safety signal for ACEIs, ARBs, and TZs and BCC and SCC, as well as for TZs and MM, was detected. An increased awareness and education, especially for those who are at high risk for skin cancer, are warranted for patients and healthcare providers. Further exploration of such associations for these commonly used drug classes is warranted.