Although cardiovascular disease (CVD) mortality rates are declining for American adults, a disparity remains between non-Hispanic Black and non-Hispanic White adults. Previous research has shown that residential segregation, a form of structural racism, experienced in childhood is associated with later-life racial and ethnic health disparities, including disparities in CVD and its risk factors. However, little is known about the health consequences of exposure to segregated schools, especially among those living in neighborhoods with high concentrations of minoritized people. This study used data from the In-School, Wave I, and Wave IV surveys of the National Longitudinal Study of Adolescent to Adult Health to examine a novel school measure of school racial segregation (Index of the Concentration of Extremes, ICE) as a predictor of Framingham 30-year CVD risk scores. We used General Estimating Equation models to evaluate the association between ICE, measured at Wave I, and two different 30-year CVD risk scores, measured at Wave IV, and examined whether the relationship varied by race. We observed that higher levels of school segregation were associated with a higher 30-year CVD risk among non-Hispanic Black participants while higher segregation was associated with a lower 30-year CVD risk for non-Hispanic White participants. This research suggests that exposure to segregation in the school setting may contribute to observed disparities in CVD among US adults.