The Dark Triad traits—Machiavellianism, psychopathy, and narcissism—are associated with manipulative, callous, and self-centeredness which may drive social dominance aspirations and interpersonal strategies. While these traits have been explored extensively in social and relational contexts, their association with body image and idealized physical traits in romantic partners remains underexplored. In this study (NMTurk = 320; 61% men) we examined the relationships between the traits and perceptions of body image, including muscularity and body fat, in both self-evaluation and partner preferences. We found that men high in Dark Triad traits perceived themselves as more muscular, whilst women high in Dark Triad traits perceived themselves as thinner, and women high in psychopathy tended have a lower Body Mass Index. Notably, partner body preferences did not differ across the Dark Triad spectrum. Our findings highlight the role of the Dark Triad traits in shaping body image perceptions and the necessary maintenance of a positive (attractive) body image in darker personalities.