The strong relationality model of relationship flourishing emphasizes the role of ethical responsiveness (how well a person intrinsically responds to the manifest or identifiable needs of others) as a direct predictor of relationship quality and as an indirect pathway for explaining the influence of vulnerabilities. This study is among the first explicit tests of the theorized role of ethical responsiveness. The sample consisted of 1432 adults in a romantic relationship, from the United States and Canada. Modeled as latent variables, ethical responsiveness served as a path between the variables of depression, anxiety, and friend and family support, and the dependent variable of relationship-focused relationship quality. Depression and friend support predicted ethical responsiveness. Ethical responsiveness, both supports, and depression predicted relationship quality. Friend support and depression had an indirect effect through ethical responsiveness. Our findings support the role of ethical responsiveness and suggest continued research into how and why it influences relationships.