Previous research has seldom used an intersectionality framework to consider how sex and race affect diabetes health, nor has it examined the role of sex and race in the well-established link between romantic relationship quality and health. This study targeted 200 adults with type 2 diabetes (46% Black; 45% female) and examined whether sex, race, and the interaction between sex and race predicted behavioral and psychological health, or moderated the link between relationship quality and health outcomes. Black women reported poorer diabetes self-care and lower self-efficacy compared to other groups. Relationship quality was associated with better self-care, increased self-efficacy, and lower depressive symptoms. The association between relationship quality and medication adherence was stronger for Black women, and the association between relationship quality and self-efficacy was stronger for both Black women and White men. Results suggest that Black women with diabetes experience more health disadvantages than other groups, but some of these disadvantages might be attenuated by supportive romantic relationships.