Research has demonstrated associations between relationship satisfaction and personality traits. Using the Actor–Partner Interdependence Model, we explored associations between self-reported relationship satisfaction in couples (n = 118) and various measures of normal and abnormal personality, including higher-order dimensions of PE/Extraversion, NE/Neuroticism, Constraint (CON), and their lower-order facets. We also examined gender differences and moderators of associations. Consistent with the Vulnerability Stress Adaptation Model, self- and partner-reported NE and PE were related to satisfaction, and their lower-order traits demonstrated differential associations with satisfaction. Further, abnormal personality traits specific to the interpersonal domain and personality disorder symptoms demonstrated effects. Relationship length emerged as a significant moderator, with associations weakening as relationship duration increased.