Objective: Gestational hyperglycemia is associated with deleterious neonatal outcomes, but long-term risks for offspring obesity are less clear. We estimated the odds for offspring adolescent overweight and obesity among mothers with gestational glucose intolerance. Methods: In a mother-offspring, historical cohort, the Israel military conscription dataset was linked to a large health maintenance organization. Included were women who were evaluated at adolescence and performed two-step gestational diabetes screening (mean age, 31 years) with a 50-g glucose challenge test (GCT), followed by a 100-g oral glucose tolerance test (OGTT) if abnormal. Glucose tolerance categories included gestational normoglycemia, abnormal GCT with normal OGTT, impaired glucose tolerance (IGT; one abnormal OGTT value), and gestational diabetes. The primary outcome was offspring overweight/obesity (BMI≥85th percentile) at adolescence, measured prior to military conscription. Logistic regression models were applied. Results: Of 33,482 mother-offspring pairs, overweight and obesity were observed in 6,516 offspring. Across increasing categories of pregnancy glycemia, the proportions of offspring with adolescent overweight/obesity increased: normoglycemia, 19%; abnormal GCT with normal OGTT, 22%; gestational IGT, 24%; and gestational diabetes, 25%, P<0·0001. Corresponding odds ratios after adjustment for mother's late-adolescent characteristics (sociodemographic confounders and BMI) and pregnancy age were 1.2 (95%CI, 1.1-1.4), 1.3 (95%CI, 1.2-1.5), and 1.4 (95%CI, 1.3-1.6), respectively. Further adjustment for offspring birth weight percentile and sociodemographic variables did not materially change results. Associations were more pronounced with increasing obesity severity. Conclusions: Gestational glucose intolerance, including categories not meeting the gestational diabetes threshold, were associated with increased odds for offspring overweight/obesity at late adolescence.