School-wide positive behavior support (SWPBS) is a systematic and effective approach for broadly improving student behavior across school environments. SWPBS includes data-based strategies for supporting all students along a continuum of need and intensity based on a three-tiered model of prevention. Students with the most significant behavioral challenges are provided with assessment-based, individualized supports. To date, considerable evaluation research has demonstrated the benefits of SWPBS, documenting behavioral improvements using the whole school as the unit of analysis. Notably, less evaluation research has focused on the effects of SWPBS on the behavior of individual students with the most significant disabilities. In this paper, we describe SWPBS with an emphasis on the conceptual and procedural elements that are intended to benefit the full range of students within a school, with a particular focus on those students with the most intense needs. We discuss the SWPBS process, provide case illustrations, and call for additional research on the inclusion of students with significant disabilities with all applications of SWPBS.