Positive behaviour support and schoolwide positive behavioural interventions and supports (PBIS) emerged in response to the misuse of behavioural theory and ableism in educational systems. Yet even with these advances, inequitable outcomes based on ability and race persist. The purpose of this article is to describe an equity-centred schoolwide PBIS approach that harnesses behavioural theory and the PBIS framework to focus specifically on systems change to lead to equitable outcomes. There is emerging evidence of promise for increasing racial equity in student outcomes, and implications and suggestions are provided to increase equity by disability status. In providing practitioners with clear steps to reduce ableism and racism in educational systems, this line of research stands to benefit all students and families.