Organizations have increasingly emphasized the role of employees as potential interventionists following acts of workplace sexism. However, sexism can be expressed in a variety of ways and bystanders may not be equally likely to recognize and intervene after witnessing different forms of workplace sexism. The current study correspondingly draws on the model of ambivalent sexism and the deontic theory of justice to propose that bystanders will experience weaker moral reactions following witnessed benevolent sexism as compared to hostile sexism and will correspondingly be less likely to intervene. We tested our hypotheses with an experimental vignette study that exposed participants to either benevolent or hostile sexism. Consistent with expectations, results showed that hostile sexism was perceived to be more of a moral violation and elicited more moral anger than benevolent sexism. Additionally, the results supported a serial mediation model in which witnessed hostile sexism (as compared to benevolent sexism) was associated with a greater willingness to intervene through perceived moral violation and moral anger. These results can inform organizational practices and empirical research aimed at understanding and improving bystander intervention willingness in response to workplace sexism.