Although feminist organizational theory frequently refers to the association between rationality and masculinity, this association tends to be stated rather than argued for. This article examines, from a philosophical and sociological perspective, how these two concepts have become genealogically so closely and inseparably intertwined. It proposes that it is the early philosophical and sociological interpretations of reason and rationality that linked masculinity and rationality. To explore the connection between rationality and masculinity that is so fundamental to management and, more broadly, organizational discourse, is the purpose of this article. Commencing with a brief overview of pre-Cartesian concepts of rationality, the main focus of the article is on modern conceptions of rationality, starting with the philosophy of Descartes. It examines the influence of the ideas of Francis Bacon, Enlightenment interpretations of rationality and the influence of Weberian rationality and subsequent interpretations of this concept of rationality by early organizational theorists. Finally, it demonstrates, via a case study of strategic management, how contemporary organizational discourse continues to reflect many of the assumptions about masculinity and rationality that are deeply embedded in more traditional organizational discourse. The article concludes with a number of suggestions for a way forward for critical gender studies that moves beyond the standard feminist critique of organizational discourse and practice.