Recent studies have found that perceived discrimination as a chronic stressor predicts poorer cognitive health. However, little research has investigated how social relationships as potential intervening mechanisms may mitigate or exacerbate this association. Using a nationally representative sample of U.S. older adults, this study examined how the existence and quality of 4 types of relationships-with a partner, children, other family members, and friends-may modify the impact of perceived discrimination on incident dementia. We analyzed data from the 2006 to 2016 Health and Retirement Study (N = 12,236) using discrete-time event history models with competing risks. We used perceived discrimination, social relationships, and their interactions at the baseline to predict the risk of incident dementia in the follow-ups. Perceived discrimination predicted a higher risk of incident dementia in the follow-ups. Although having a partner or not did not modify this association, partnership support attenuated the negative effects of discrimination on incident dementia. Neither the existence nor quality of relationships with children, other family members, or friends modified the association. Our findings imply that intimate partnership plays a critical role in coping with discrimination and, consequently, influencing the cognitive health of older adults. Although perceived discrimination is a significant risk factor for the incidence of dementia, better partnership quality may attenuate this association. Policies that eliminate discrimination and interventions that strengthen intimate partnerships may facilitate better cognitive health in late life.