The purpose of this research was to examine participation in physical activity and social media addiction among university students. A total of 462 university students from 3 different universities voluntarily participated in the study. In the study, the "Motivation Scale for Participation in Physical Activity" and "Facebook addiction scale" were used as data collection tools. In the study, the independent sample t-test and One-way ANOVA test were applied for normally distributed data depending on the number of variables. Also, correlation analysis and regression analysis were used. According to the simple linear regression analysis conducted to determine the effect of motivation on participation in physical activity on social media addiction, it was determined that the model established was statistically significant (F=70.305; p<0.05) and the ratio of explanation of the dependent variable by the independent variable was R2=0.182. It was determined that the most important factor that motivates students to participate in physical activity is individualistic reasons. Individualistic reasons were followed by environmental and causality factors, respectively. The results of the study show that students' participation in physical activity and social media addiction was not significantly differ in terms of their gender. [This study was presented as an oral presentation at ERPA International Congresses on Education, 10-12 April 2020.]