How are different social relationships jointly and uniquely associated with older women's health and well-being, and what is the directionality of these associations? We address these questions using longitudinal data from the Midlife in the United States study. We find that relationship quality with romantic partners, family, and friends is positively linked with better health and well-being concurrently and longitudinally. Cross-lagged analyses indicate that romantic relationships are more predictive of than predicted by health and well-being, family relationships are more predicted by than predictive of health and well-being, and friendships are both predicted by and predictive of health and well-being.