The role of the school leader (principal) in supporting educational reform is explored through a case study of one high school implementing the Three Block Model of UDL (Katz, 2012a) in an effort to meet the needs of a diverse student population. This case study is a part of a much larger study exploring outcomes for students and teachers of implementing the model with social and academic inclusion as a goal (Katz, 2013). In this article, analysis of the principal's field notes, photographs, and video evidence is detailed to illuminate a process for supporting inclusive education through teachers' professional development in universal design for learning. Results indicated the principal's efforts to provide teachers with professional development, planning time for collaboration, vision, and direct involvement in instructional delivery resulted in positive outcomes for both students' and teachers' learning, self-efficacy, and sense of community. (Contains 1 figure.)