<p>In general, women intervene as bystanders more often than men to prevent or disrupt sexual assault. Gender socialization, including internalization and adherence to aspects of traditional gender role norms, may help explain this gender disparity in prosocial bystander intervention. We examined the association between conformity to masculine norms for college men (<i>N</i> = 412) and conformity to feminine norms for college women (<i>N</i> = 742) and bystander intervention (i.e., bystander attitudes, efficacy, intentions, and behaviors). Results indicated that higher endorsement of the masculine norms of asserting masculine dominance over women, being perceived as heterosexual, and controlling one’s emotions were associated with less bystander intervention among men, while engaging in more risk-taking behaviors was associated with more bystander intervention after controlling for the other norms. For women, endorsing feminine norms about restricting sexuality outside of a committed relationship and prioritizing romance were predictive of less bystander intervention, while conforming to norms about being perceived as nice and valuing friendship predicted more bystander intervention. These findings suggest that the specific aspects of gender role norms, rather than masculinity or femininity more generally, may be contributing to gender differences in intervention rates, and that men and women who identify with traditional gender roles may face competing pressures when confronted with sexual violence intervention opportunities. Parsing these associations has implications for gender socialization and bystander theories, as well as developing effective bystander training programs that deconstruct gender norms.</p>