With Australian disability discrimination legislation and educational policy promoting movement toward inclusive education, the building and supporting of inclusive education workforce capability is of paramount importance. This study investigated how principals in Australian primary and secondary educational settings support teachers to provide inclusive education and what these principals perceive to be barriers to supporting the education workforce to deliver inclusive education. The study used an online open- and closed-set survey. The findings demonstrated that principals in educational settings across the government, Catholic and independent sectors and across geographical regions offered largely similar professional learning opportunities to their staff, and expressed similar views about barriers and principals' roles in supporting their teachers to deliver inclusive education. Participants overwhelmingly reported that their role in building teacher capability was as instructional leaders and brokers of workforce professional learning. There was a strong indication by principals of the need for teachers' knowledge and skills to be developed and of the need for high quality, effective ongoing professional learning. Participants reported barriers to supporting teachers to deliver inclusive education, most commonly an insufficiency of time, finances, and access. Recommendations for better supporting teachers in primary and secondary settings to deliver inclusive education are made.