Objective: Hispanic and Black children in the US are disproportionately affected by obesity and other biological and social predictors of type 2 diabetes compared to non-Hispanic White (NHW) children. No surveillance study has established prediabetes prevalence in children <12 years, and pediatric testing guidelines are limited. This study examined prediabetes prevalence and relationships between demographic factors and prediabetes in vulnerable youth. Research Design and Methods: Measures collected at 16 elementary schools on 976 3rd-5th graders (7-12 y) included age, sex, ethnicity, free/reduced-price school lunch (FRL) status, self-reported parent educational attainment, BMI, and prediabetes status determined from fasting plasma glucose (FPG) and HbA1c. Multivariate regression was used to examine cross-sectional associations between demographic variables and FPG, HbA1c, and prediabetes status. Results: The cohort consisted of children (n=976; age 9.3±0.09) who were 47% female, 67% Hispanic, and 10% Black. Approximately 71% of the children received FRL, 50% had overweight/obesity, and 26% had prediabetes. Prediabetes rates were 2.8 and 4.9 times higher in Hispanic and Black versus NHW children, respectively (p≤0.001), and 1.5 times higher in children with obesity versus normal BMI (p=0.02). Children of parents with an 8th grade education, some high school education, or a high school degree had 3.1, 2.8, and 2.3 times higher odds of having prediabetes compared to children of college graduates, respectively (p≤0.003). Analyses with FPG and HbA1c yielded similar results. Conclusions: These findings highlight the need for early screening, more comprehensive testing guidelines, and prevention programs tailored toward minority children, children with obesity, and children of parents with low educational attainment.