Understanding achievement and discipline trajectories of Latinx students is critical given disproportionate dropout/pushout rates of Latinx students from schools across the U.S. Using a Critical Race Theory framework, the current study examined longitudinal associations amongst a sample of (N = 1672) Latinx youths' school readiness at kindergarten entry and their subsequent academic achievement and discipline violation assignments in high school, also examining the associations with gender, socioeconomic status, English language status, and special education status. A moderated mediation analysis found that high school achievement fully mediated the negative association between kindergarten readiness and high school discipline outcomes. Gender, SES, and English language status were all found to have non-significance or poor fit as moderators. The association between kindergarten readiness and high school achievement was significant for students in general education but not in special education. Implications related to these findings, early assessment, intervention, and best school discipline practices are discussed.