Background Gestational diabetes mellitus is associated with adverse maternal and fetal outcomes and increases subsequent risk of Type 2 diabetes. Researchers have shown that breastfeeding may reduce diabetes risk in women with recent gestational diabetes. Research aim To assess association between infant feeding and postpartum glucose tolerance in mothers with recent gestational diabetes within 1 year postpartum. Methods A literature search was performed up to December 31, 2019, retrieving articles related to infant feeding, gestational diabetes, and postpartum glucose regulation in four major databases (PubMed, Cochrane, CINAHL, and Embase). Methodological quality was assessed using tools from the United States National Institutes of Health and the National Heart, Lung, and Blood Institute. Results The search yielded 15 cohort studies meeting the selection criteria. Of the 15 studies, 13 (86.7%) examined the influence of breastfeeding on postpartum glycemic status, and eight (53.4%) compared the mean blood glucose values between breastfeeding and non-breastfeeding participants. Of the 13 studies that compared postpartum glycemic status, nine (60%) of the research teams found that breastfeeding lowered rates of impaired glucose tolerance, and four (26.7%) showed no significant change. In eight of the studies reporting mean blood glucose values, six (75%) reported significantly lower fasting plasma glucose in breastfeeding participants, with reductions ranging from 3.7 to 7.4 mg/dL (0.2-0.4 mmol/L). Conclusion Breastfeeding has been associated with improved postpartum glucose regulation in mothers with gestational diabetes. In pregnant women with gestational diabetes, breastfeeding may reduce the risk of Type 2 diabetes, and women with gestational diabetes should be strongly encouraged and supported to breastfeed.