The role structure of a TMT—the roles of TMT members and the relationships among those roles—has important implications for how TMT members work together as a group in directing an organization and shaping its strategy. Although the importance of TMT role structure has long been noted, it has received scant attention until recently when upper-echelons scholars started examining its formation and influence. To stimulate a concerted effort in studying TMT role structure, we develop a framework elaborating its main themes, draw out key contributions of publications in the SMS journals and beyond, and outline promising future directions. In particular, we highlight important dynamics of how formal and informal structures complement or compete with each other in the strategic leadership of an organization.