Executive function (EF) has rarely been considered for adolescents' daily school outcomes or in conjunction with ethnic/racial discrimination. Using 2-week, daily data from 137 ethnic/racial minority adolescents (M[subscript age] = 14.56; 53% female; 56% Black, 19% Latinx, 7% Asian, 7% Native, 12% other [e.g., multiracial]) in the Midwest United States, this study examined same-day, within-person associations between EF and school engagement (controlling for prior-day engagement), and how these associations varied by adolescents' daily experiences of ethnic/racial discrimination. Two EF components, inhibitory control and working memory, were associated with higher levels of school engagement on the same day, only on days when adolescents reported lower than their typical levels of discrimination. An alternative, indirect effect (i.e., discrimination compromised same-day school engagement via EF) was not observed. Findings highlight novel mechanisms through which discrimination may contribute to educational disparities.