Previous studies have yielded controversial results about the link between tumor necrosis factor-α (TNF-α) gene polymorphisms (rs1800629, rs361525, and rs1799724) and risk of gestational diabetes mellitus (GDM). Thus, a meta-analysis was performed to obtain a more conclusive result. Eligible studies were retrieved in PubMed, Embase, China National Knowledge Infrastructure, and Wanfang databases on February 18 2020. Odds ratios (ORs) with 95% confidence intervals (CIs) were utilized to evaluate the relationship between TNF-α polymorphisms and GDM susceptibility in five genetic models. The subgroup stratified analysis and trial sequential analysis (TSA) were both performed. In total, 15 studies on TNF-α polymorphism including 1289 GDM patients and 1445 healthy women were identified. For rs1800629, significant associations were found in Asian subgroup in five genetic models (for example: allele model, p = .001, OR = 2.20, 95% CI = 1.38-3.52). The existing samples were adequate revealed by TSA, which reached a shred of solid evidence. No association was observed between TNF-α rs361525 and rs1799724 polymorphisms with the GDM risk within all genetic models (p > .05). For Asian populations, TNF-α rs1800629 is a risk factor for GDM. There was no association between two TNF-α polymorphisms (rs361525 and rs1799724) and GDM under all genetic models. More multi-ethnic and larger sample size studies are needed to confirm these null associations.