The benefits of student-teacher ethnoracial matching on student outcomes—ranging from academic achievement to postsecondary attainment—are well documented. Yet, we know far less about the role of student-teacher ethnoracial matching in the earliest grades school and on less about effects on non-academic outcomes. The purpose of this study is to advance our understanding of student-teacher ethnoracial matching in early elementary school by exploring two executive function outcomes – working memory and cognitive flexibility. Drawing on data from the Early Childhood Longitudinal Study – Kindergarten Class of 2011, our findings suggest student-teacher ethnoracial matching benefits on working memory skills, though not cognitive flexibility. Observed associations for working memory are of similar size to those for academic achievement outcomes and are largest for Black and Latinx students.