Background: Existing knowledge suggests that gestational diabetes mellitus was inconsistently associated with children allergic diseases. The aim of this study was to identify the association between gestational diabetes mellitus (GDM) and the risk of children allergic diseases by systematic review. Methods: We searched and retrieved three databases (PubMed, Web of Science and Cochrane Library) for articles on the association between GDM and children allergic diseases published before December 31, 2019. Stata software version 16.0 was used for statistical analysis. Results: Eight published studies were included in this meta-analysis. The pooled effect estimates showed the association between GDM and allergic outcomes, including asthma (OR:1.13,95%CI:1.01-1.27), wheezing (OR:1.12,95%CI:1.08-1.16), and atopic dermatitis (OR:1.41,95%CI:1.31-1.53). GDM was not associated with the risk of allergic sensitization, with a pooled effect estimate of 1.45 (95%CI: 0.40, 5.23). Conclusion: GDM may increase the risk of allergic diseases in children. However, this finding should be validated with future large-sample epidemiological studies covering a wider spectrum of allergic diseases.