Skin tone-based social stratification is an enduring part of the U.S. racial landscape. Despite literature finding that skin tone informs educational outcomes among adults, few studies have examined these processes in early childhood. The current study tested whether skin tone predicted Mexican-origin 5-year-old children's academic readiness (i.e., applied problems and letter-word identification) and whether relations were modified by ethnic-racial identity (i.e., positive attitudes and centrality). Findings indicated that darker skin tones predicted lower applied problems scores, an indicator of early math ability. Positive ethnic-racial attitudes did not moderate the relation between skin tone and academic readiness. However, contrary to our hypothesis, higher ethnic-racial centrality "strengthened" the association between darker skin tone and lower letter-word identification, an indicator of early reading skills. Findings suggest that there is early development of within-race skin tone-based disparities in education, and underscore the need for further exploration of children's ethnic-racial identity in these processes.