Purpose The aim of this study was to report our experiences of sleeve gastrectomy (SG) in obese patients with type 1 diabetes mellitus (T1DM) and to assess its metabolic outcomes through a review of the literature and a meta-analysis. Materials and Methods We conducted a retrospective review of the electronic medical records of all patients who underwent bariatric surgery between January 2008 and February 2019 at a single institution. A literature search was performed using PubMed, Cochrane library, and Embase, and a meta-analysis for each direct comparison between pre- and postoperative groups was performed using the random effects DerSimonian–Laird method. Results We identified three obese patients with T1DM who underwent SG. The baseline body mass index (BMI), HbA1c, and total daily insulin dose was 40.8 (37–47.4) kg/m 2 , 7.1% (6%–7.7%), and 92.3 (54–113) units, respectively. After surgery, the BMI and total daily insulin dose reduced to 32.2 (30.2-37.6) kg/m 2 and 22.3 (12-40) units, respectively. However, the HbA1c increased to 7.8% (5.4%-10.8%). In the meta-analysis, the weighted mean reduction in BMI, HbA1c, and total daily insulin dose were 10.69 kg/m 2 (95% CI 7.01-14.37, P<0.00001, I 2 =0%), 0.3% (95% CI −0.10–0.71, P=0.1447, I 2 =0%), and 58.52 units (95% CI 15.96-101.08, P=0.07, I 2 =0%), respectively. Conclusion SG showed excellent weight-reducing effects during a short follow-up period in obese patients with T1DM and improved the glycemic control by reducing insulin requirement.