Voice—or the expression of ideas, concerns, or opinions on work issues by employees—can help organizations thrive. However, we highlight that men and women differ in their voice self-efficacy, or the personal confidence in formulating and articulating work-related viewpoints. Such differences, we argue, can impede women’s voice from emerging at work. Drawing on social cognitive theory (SCT), we propose that women tend to develop greater voice self-efficacy and thereby speak up more when they have the opportunity to observe female rather than male leaders speak up. Hence, we point to the potential absence of women leaders who can role model speaking up at work as a likely inhibiter of women’s voice. Using data from a correlational field study involving 368 employees and their leaders from a variety of industries in India and an experimental study in an online panel of 546 US-based workers, we found support for our hypotheses. We discuss the implications of our research for theory and practice.