© 2020 Elsevier LtdThe use of social media is rapidly becoming widespread day by day. However, with the excessive use of social media and the Internet, individuals' functionality decreases, and this situation begins to become an addiction. In the literature, the relationship between dark triad personality traits and addiction behaviors was examined; however, contradictory results were found. This study aims to examine the mediating roles of death anxiety and life satisfaction in the nature of the relationship between dark triad personality traits and social media addiction. The sample consists of 364 people (219 females 144 males) between the ages of 18–35. Socio-demographic Information Form, Social Media Addiction Scale, Satisfaction with Life Scale, Thorson-Powell Death Anxiety Scale, and Short Dark Triad Scale were used for data collection. According to the results, death anxiety mediated the relationship between Machiavellianism and social media addiction; life satisfaction mediated the relationship between narcissism and social media addiction; for both life satisfaction and death anxiety mediated the relationship between psychopathy and social media addiction. This research contributes to literature and psychotherapy practices by revealing the importance of life satisfaction and death anxiety in the relationship between social media addiction and dark triad.