The research in this paper is the first large-scale quantitative study to look at teacher autonomy and its importance for retention in England. It finds that teacher autonomy is strongly correlated with job satisfaction, perceptions of workload manageability and intention to stay in the profession. It also finds that the average teacher has a lower level of autonomy compared to similar professionals. Teachers' autonomy over their professional development goal-setting is particularly low, and is the most associated with higher job satisfaction. Increasing teachers' autonomy, particularly over their professional development goals, therefore has great potential for improving teacher job satisfaction and retention. In the light of the findings, the authors draw out the implications for policy and practice and make recommendations for school leaders and policymakers. An appendix is included in the paper. [This report was prepared in partnership with the Teacher Development Trust.]