In light of the growing number of women in the upper echelons, it is necessary to integrate and synthesize research on women at the top of corporations. The extant literature occurs in several disciplines—appearing in the fields of management, strategy, finance, economics, organizational behavior, ethics, sociology, and industrial relations—and is disparate and fragmented. A large and growing set of scholars provide various theoretical perspectives and empirical findings addressing organizational demographics, supply side factors, and outcomes. A number of theories are employed to understand the issue of women in the upper echelons, including resource dependence, tokenism and critical mass, glass cliff, social identity, human capital, social capital, and signaling theories. Most articles use U.S. data and tend to deal with the effect of female CEOs or that of female representation on corporate boards and top management teams (TMTs) on various firm-level outcomes. The majority of the studies investigate a potential relationship between gender diversity and financial performance. Research on this topic can guide policy and practice, improving the performance of organizations and the individuals who work within them.