The purpose of this study is to investigate the direct and indirect effects of Dark Triad (DT) traits (Narcissism, Machiavellianism, and Psychopathy) on Instagram addiction by considering the mediating roles of motives (social, conformity, enhancement, and coping). Data were obtained from 315 Instagram users in Oman and analyzed using the Partial Least Square (PLS) technique. The results indicated that Narcissism, Machiavellianism, and Psychopathy have a positive and significant effect on Instagram addiction. Conformity, enhancement and coping motives were found to mediate the influence of Narcissism on Instagram addiction. Conformity motive mediated the Machiavellianism–Instagram addiction link and coping motive mediated the Psychopathy–Instagram addiction link. Psychologists, social scientists, tech-oriented individuals, organizations, and policy makers would benefit from this study by unlocking the potentials of measures to prevent Instagram addiction.