Throughout American history, formal laws and social norms have discouraged interracial romantic relationships. Interracial relationships blur the boundaries between racial groups, challenging the essentialized racial categories that define Whiteness as an exclusive, high status identity. Whites, who are the most resistant to interracial marriage of any racial group, have used their dominant position in American society to enforce norms against interracial relationships. Despite the importance of racial homogamy to White identity and status, we argue that gender roles make violating norms against intimate intergroup contact more costly for women than men, leading to Whites’ greater resistance to interracial relationships involving White women. In a representative American sample using a natural quasi-experiment, as well as three follow-up lab experiments, we find that White women face differential social penalties for intimate intergroup contact — being perceived as gender deviant and low status within the group. By contrast, having a racial out-group partner did not influence status perceptions of men or Black women. Status perceptions of both individuals in the couple predicted attitudes toward the couple as a unit, leading to greater prejudice toward interracial relationships involving White women than White men. This research demonstrates the existence of a gendered double standard for intimate intergroup contact among Whites, revealing that gender norms play a critical role in the maintenance of American racial boundaries.