Aim:The aim of this study is to investigate the relationship between social media addiction and optimism/pessimism among adolescents. Using a descriptive design, the study was conducted with 231 high school students. A "Descriptive Data Form," the "Social Media Addiction Scale for Adolescents" and the "Optimism-Pessimism Scale for Adolescents" were used as data collection tools. The students' mean score on the Social Media Addiction Scale was calculated to be 15.29±2.42 and accordingly. Results: The results of the study showed that male students used social media more frequently and it was seen that the father's education had an impact on the level of social media usage. It was found that the students' attitudes of optimism varied depending upon their gender, class, income level, information-sharing on social media, and how much they used social media to pass the time. While a statistically significant, positive but weak correlation was seen between social media usage and optimism, the correlation with pessimism was statistically significant, negative, and weak.