This article discusses the impact of a professional learning activity called the Principals as Literacy Leaders (PALL) program on the capacity of school leaders to engage, involve, and support teachers and their school communities to develop a shared moral purpose for making their school more effective in assisting students to become more able readers. It uses data collected from participants in the PALL program together with case study data collected from five Tasmanian schools to analyse the actions by school leaders to develop a shared moral purpose related to facilitating higher levels of student learning in reading. The study shows that school leaders felt more capable in their ability to lead their schools after completing the program and that the development of a shared moral purpose led to improved teaching practices and higher levels of student engagement, students' ability to talk about their learning, and better achievement in reading.