Teachers play a major role in the success of educational reform, and reforms impact teachers in different ways. This paper explores the relationship between teacher identity and school reform: how a reform affords or constrains teacher professional identity construction, and how teacher identity construction enhances or hinders reform enactment. By employing two theoretical lenses, teacher leadership and teacher identity, we analysed six individual cases of leading teachers in one reform-affiliated Israeli school over a three year period, and examined (a) their professional identity construction and (b) their involvement in reform enactment and development, within their teacher teams, schools and district. Detailed analysis of three of these cases exemplifies three different identity trajectories and reform enactment within the same school. This study expands our understanding of the development of educational reforms, illuminating: (1) the reciprocal relationship between teacher professional identity construction and reform development; (2) the crucial role reform structures can play in constructing and enacting teacher leadership; and (3) the methodological affordances of analysing teachers' reform enactment at multiple levels, including team, school and district levels.