Purpose: Intermittent attention to the district as the unit of study has left a void in our understanding of the complexities associated with the ability of district-level leaders to contribute to successful, systemic educational reform. In this article, the authors address this void by providing a narrative synthesis of previous findings, proposing a theory of districts as institutional actors in systemic reform with the goal being to increase achievement and advance equity, and suggesting areas of future research that extend our understanding of districts as institutional actors in educational reform and build our knowledge of reform that improves achievement and advances equity. Proposed Conceptual Argument: The four roles of districts evident in research to date are (a) providing instructional leadership, (b) reorienting the organization, (c) establishing policy coherence, and (d) maintaining an equity focus. These four roles, which are interdependent, variably coupled, and coevolving through a non-linear process, serve as a foundation for the authors' proposed framework of districts as institutional actors in improving achievement and advancing equity. Implications for Research and Practice: The discontinuous and limited nature of previous research has contributed to the lack of theoretical advancement with regard to a research-based understanding of district reform and thus to a lack of research-based guidance for district leaders to follow to create systemically districts that improve achievement and advance educational equity for all children. The framework presented here contributes toward the resolution of these issues by developing an intentional, coherent, and integrated framework of districts as institutional actors in reform. (Contains 1 figure and 27 notes.)