Ostracism and dark triad personality traits have been found to be linked with social media addiction. Despite the well-established relationship between the dark triad (i.e., narcissism, machiavellianism, and psychopathy) and social media addiction, there is limited research on their mediating effect. In the present study, we tested a hypothetical model to examine the mediating effect of the dark triad on the relationship between ostracism and social media addiction. Data were collected from 497 Turkish adolescents (M = 14.98, SD = 0.93) who regularly use social media. Participants completed measures of ostracism, dark personality traits, and social media addiction. The results of the mediation analysis showed significant relationships among ostracism, social media addiction, and the dark triad. Specifically, the dark triad variables acted as mediators in the relationship between ostracism and social media addiction. The present study also highlights the importance of dark personality traits as a mediator of the relationship between ostracism and social media addiction. The implications of these results extend to the development of interventions aimed at mitigating social media addiction among adolescents. Ultimately, this study offers valuable insights into the contributing factors that underlie the detrimental effects of social media on the mental well-being of adolescents.