||A variety of individual differences in aspects of self-regulation (e.g., grit, self-control, conscientiousness) predict important life outcomes, such as wellbeing, vocational success, and physical health. Most conceptual models of these associations emphasize intrapersonal processes (e.g., inhibition, planning, problem-solving). However, interpersonal processes may also contribute to the positive outcomes associated with better self-regulation. We used a sample of 200 university student participants to identify potential interpersonal mechanisms that relate grit, self-control, and conscientiousness to social outcomes. Specifically, we examined whether interpersonal processes (i.e., trait social behavior), described by the interpersonal circumplex, mediated the association of self-regulation with social support, loneliness, interpersonal problems, and negative experiences. In correlational analyses, self-regulation variables were consistently associated with social outcomes. Grit and conscientiousness were significantly associated with dominant and warm trait social behavior, and self-control was associated with warm behavior. Further, interpersonal warmth and dominance partially mediated the association of grit with less loneliness and interpersonal problems; dominance partially mediated the association of grit and greater social support. Warm interpersonal style partially mediated the association of self-control with greater perceived social support and less loneliness and interpersonal problems. Lastly, warm and dominant interpersonal style partially mediated the association of conscientiousness with greater perceived social support and less loneliness and interpersonal problems. Hence, interpersonal processes may contribute to the effects of individual differences in self-regulation.