This article reviews the small but emerging literature on men who become allies against sexism. Although men are less likely than women to recognize sexism, male allies possess psychological belief systems that allow them to overcome barriers to seeing sexism and thus recognize the unfair treatment of women. We review research demonstrating that relative to women who confront sexism, men who act as allies are evaluated more positively, while their confrontations are taken as more serious and legitimate efforts to combat sexism. We discuss the implications of this research, including a discussion of how individuals and organizations can encourage men to become allies. We also identify how women can take advantage of the insights gleaned from men's confrontations to become more effective when they confront sexism.