Masculinity ideology has been found to negatively impact many educational,health, and psychological consequences for men and can be particularly consequential for their romantic relationships. Knowledge regarding how masculinity ideology impacts women’s relationship experiences is scant in the literature and there is limited research suggesting that partner’s masculinity ideology can impact women’s relationship experiences. Given the negative consequences of masculinity ideology on relationship experiences for men and women, I examined how masculinity impacts romantic relationship outcomes in two studies. Study 1 investigated the role of men’s and women’s masculinity ideology and men’s gender role conflict (GRC) on relationship self-efficacy. Hierarchical regression analyses revealed that masculinity ideology was not associated with relationship self-efficacy and further gender was not a significant moderator. Men’s gender role conflict was found to relate to relationship self-efficacy significantly and negatively. In a new sample of emerging adults, Study 2 investigated how masculinity ideology impacts three relationship outcomes: relationship self-efficacy, relationship satisfaction, and sexual satisfaction. I further explored the association between women’s masculinity ideology and their perceived partner’s gender role conflict on women’s relationship outcomes. Masculinity ideology was negatively related to all relationship outcomes, but this association was stronger for women for relationship satisfaction and relationship self-efficacy. Women’s perceptions of their partner’s GRC negatively predicted all relationship outcomes. Specifically, the interaction of partner’s GRC and women’s masculinity ideology was significant for relationship self-efficacy, such that the association between women’s masculinity ideology and relationship self-efficacy was more positively related when women’s partners had greater GRC. Findings from the current dissertation study provide intriguing first steps in identifying the negative consequences of masculinity ideology for men and women and provide novel steps toward understanding how partner’s masculinity may impact women’s relationship outcomes.