We assessed the effects of a whole-school equity intervention implemented within a school-wide positive behavioral interventions and supports (PBIS) framework on racial inequities in school discipline in eight elementary schools with inequitable referrals for Black students. The intervention involved assessing patterns of racial disparities in school discipline decisions and providing professional development on adapting school-wide behavior systems to improve cultural responsiveness through concrete strategies targeting the patterns. After consent and matching on existing levels of racial inequities, half of the schools were randomly assigned to receive the intervention. Analyses showed that schools receiving the intervention had significant decreases in racial disparities in school discipline and rates of office discipline referrals (ODRs) for Black students, while control schools had minimal change. Results are discussed in terms of improving equity in school discipline within multitiered systems of support.