Background: Bariatric surgery plays a pivotal role in the management of obesity and metabolic disorders, including type 2 diabetes mellitus (T2DM). However, the relative efficacy of different surgical procedures in achieving durable T2DM remission remains unclear. Methods: A systematic review and network meta-analysis (NMA) were conducted according to PRISMA-NMA guidelines. Searches were performed across PubMed, Embase, Scopus, and Cochrane Library (2000–2024). Eligible studies included randomized controlled trials and prospective cohorts comparing sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and one-anastomosis gastric bypass (OAGB). The primary endpoint was complete T2DM remission (HbA1c