Objective: The objective of this study was to investigate the relationship between distress tolerance, Dark Triad personality traits, and marital conflict, with ego strength as a mediating variable, in women seeking divorce. Methods and Materials: The study utilized a descriptive-correlational design and included a sample of women seeking divorce who visited marital counseling clinics in District 3 of Tehran during the spring of 2024. Data were collected using self-report questionnaires: the Marital Conflict Questionnaire, the Short Dark Triad Personality Questionnaire (SD3), and the Psychological Ego Strength Inventory (PIES). Structural equation modeling (SEM) was employed for data analysis. Findings: The results revealed that distress tolerance had an indirect and significant effect on marital conflict through the mediation of ego strength (β = -0.366, p = 0.001). Among the Dark Triad traits, Machiavellianism showed an indirect and significant effect on marital conflict (β = 0.170, p = 0.001), while psychopathy and narcissism did not exhibit significant indirect effects. Narcissism had a direct positive effect on marital conflict (β = 0.275, p = 0.000), whereas psychopathy and Machiavellianism did not have direct effects. Ego strength had a significant negative effect on marital conflict (β = -0.595, p = 0.000). Conclusion: Machiavellianism indirectly influences marital conflict through the reduction of ego strength, while narcissism has a direct positive effect on conflict. Ego strength plays a key role in reducing marital conflict, suggesting that interventions aimed at enhancing ego strength and addressing manipulative personality traits may be effective in mitigating marital conflict among women.