OBJECTIVE To compare the prevalence of parental diabetes between children with and without type 1 diabetes (T1D), and to compare clinical characteristics at diagnosis of T1D in children with, versus without, a family history of diabetes. RESEARCH DESIGN AND METHODS Parental diabetes among children with T1D was compared with a general population cohort. Clinical characteristics were compared by family history of diabetes in parents and grandparents of 3,603 children with T1D using relative risk (RR) and ANOVA. RESULTS Children with T1D more often had parents with type 2 diabetes (T2D) (RR 1.88; P < 0.001) than did children without diabetes. Children with T1D and a family history of T2D were more likely to be overweight or obese (P = 0.002). CONCLUSIONS A family history of T2D and being overweight may contribute to increased risk of T1D.