Bariatric surgery is an effective treatment option for patients with type 2 diabetes mellitus (T2DM) and obesity. This study aims to compare the effects of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) on remission of T2DM. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched for studies published between database inception and 21 November 2019. A meta-analysis, using a random effects model, was performed to calculate relative risk (RR) of T2DM remission between the groups in randomized controlled trials (RCTs). Of 2650 records identified, 12 records from 10 different RCTs were finally included. The studies comprised 705 patients with follow-up from 1 to 5 years. The remission rate of T2DM at 1 year was higher among those undergoing RYGB (156/276, 57%) compared with those undergoing SG (128/275, 47%), RR (95% CI) 1.20 (1.00-1.45), P = .047, I = 24.9%, moderate-quality evidence. Among studies with 2- to 5-year follow-up, there was no difference in remission rates between the RYGB (132/263, 50%) and SG (121/266, 46%) groups, RR 1.06 (0.94-1.20), P = .34, I = 0.0%, low-quality evidence. RYGB resulted in a higher rate of T2DM remission compared with SG after 1 year. The T2DM remission rates did not differ in studies with 2- to 5-year follow-up.