The aim of this study is to determine the social media addiction levels of university students and examine whether their social comparison orientations and ruminative responses significantly predict social media addiction. The study group consists of 261 university students. "Social Media Addiction Scale", "Iowa-Netherlands Social Comparison Orientation Measure" and "Ruminative Response Scale, Short Form" were applied to the participants. Frequency, percentage and multiple regression analysis were used to analyse the obtained data. As a result of the study, it was found out that university students were less addicted on social media. As a result of the regression analysis, it was determined that obsessive thinking, deep thinking and social comparison had significant effects in predicting social media addiction. It was concluded that obsessive thinking and social comparison predicted positively, whereas deep thinking alone was not a significant predictor. The obtained findings were discussed in the context of the relevant literature and suggestions were made for further research.