We advance gender inequality scholarship by drawing attention to a growing but understudied group: young, single women professionals (without children). Our thesis is that for women, singlehood is deemed incongruent with role expectations of leadership – both with masculine expectations of men as “ideal leaders”, but also compared to feminine expectations of women leaders as communal, relational. We predict this incongruity to be most penalizing for analytically-talented, single professional women who are seen as gender incongruent for their masculine skills and for prioritizing their careers. Leveraging a multi-method approach, we present evidence in support of our thesis. In Study 1, a set of experiments, we observe participants evaluate single analytically-talented women as least suitable for a leadership promotion compared to identically-described single men, married men and women. Participant explanations for their negative evaluations support incongruity as the mechanism for the penalty toward single women, whom they describe as “too analytical”, lacking the people management skills needed for leadership. Study 2 adds external validity by examining early career promotions of MBA graduates, where single analytically-talented women prove the least likely to advance post-graduation compared to all other gender, marital status, and talent groupings. The combined studies unveil a novel penalty directed at young, single, analytically-talented women professionals in their early careers for their perceived incongruity with gendered expectations of masculine and feminine leadership.