This article focuses on an initiative aimed at transforming teachers' professional learning in mainstream schools in Kazakhstan through a particular approach to the provision of support for teacher leadership. It draws on an intervention in four schools in Kazakhstan leading to the launch of a three-year strategy to develop support for teacher leadership nationwide. Outcomes of the study are accounted for in narrative form. The context of the initiative is a post-Soviet country striving for modernisation. An intense period of education reform and the nature of the education system means that teachers' capacity for professional learning is hindered by the organisational structures within which they work and the absence of strategies to empower them as professionals. The article includes a conceptual exploration which considers the role of leadership as a dimension of teachers' professionality and the leadership practice of school directors who have the potential to create the organisational conditions within which teachers can become more agential in the development of their own practice. The analysis highlights the importance of the school as a learning organisation and the role of support for teacher leadership as a tool for the transformation of teachers' professionality and practice within their schools.