This second edition of Teacher Agency brings new perspectives on teachers as agents of change and development within their professional ecosystems. Centred around an ecological theory of agency, it critically surveys the work that has emerged in this field in the decade since its first edition and how international trends in curriculum policy and teacher development have shaped that landscape. As well as updating the research that formed the core of its original study, this second edition now includes an extensive literature review spanning the theory and conceptualization of teacher agency, and the critical issues that now affect it. Two new chapters also now discuss agency in relation to two key dimensions of education - curriculum and teaching. Drawing this research together with the authors’ international experiences and perspectives, Teacher Agency grapples with theoretical and practical issues of international significance – how should agency be understood? How does it relate to individual teachers’ capacity? What does this mean for the cultures and structures at the heart of teaching?