Abstract Objective: Women born preterm or with low birthweight (LBW) have an increased future risk of gestational diabetes mellitus (GDM); however, a quantitative summary of evidence is lacking. Herein, we aimed to investigate whether LBW, small for gestational age (SGA) status, or preterm birth are factors associated with GDM risk; moreover, the evidence quality was assessed. Data Sources: We searched databases such as MEDLINE, Embase, and CINAHL and study registries including ClinicalTrials.gov and ICTRP from launch until October 29, 2020. Methods of Study Selection: Major electronic databases were searched from inception to October 29, 2020. Observational studies that examined the association between birth weight or gestational age and GDM were eligible. We pooled the odds ratios and 95% confidence intervals using the DerSimonian and Laird random-effects model. Tabulation, Integration, and Results: Eighteen studies were included (N = 827,382). The meta-analysis showed that being born preterm, with LBW, or with SGA status increased the risk of GDM (pooled odds ratio = 1.84; 95% confidence interval: 1.54 to 2.20; I2 = 78.3%; τ2 = 0.07). Given a GDM prevalence of 2.0%, 10%, and 20%, the absolute risk differences were 1.6%, 7.0%, and 11.5%, respectively. The certainty of evidence was low due to serious concerns of risk of bias and publication bias. Conclusion: Women born prematurely, with LBW, or with SGA status may be at an increased risk of GDM. However, whether this should be considered in clinical decision-making depends on the prevalence of gestational diabetes mellitus. Protocol registration: PROSPERO (CRD42020142004)