This chapter explores professional learning and professional development of teachers, principals, and other educators. It initially identifies our understanding of the terms professional learning and professional development and various national political ideologies and policies that have influenced the work in this area. In particular, the chapter explores some key themes that researchers in the PEP network have addressed related to professional learning and development. Firstly, we explore three broad themes: Action research for professional learning, professional learning for social justice, and leading for learning. Secondly, we examine more specific themes of professional learning at different stages of a teacher’s career. The concepts of praxis and bildung are highlighted as important understandings that guide our work. The chapter discusses the contribution that this research makes to the professional learning and professional development literature more broadly and concludes with a reflection on what we have achieved. We also present a composite theoretical framework for understanding professional learning as praxis development.