This study, which examines the relationship between physical activity, social media addiction and life satisfaction in high school students, was conducted to understand the possible link between physical activity levels and social media use among high school youth and the effect of this situation on life satisfaction. Relational survey method, one of the quantitative research methods, was used in the study. The sample of the study consists of 300 students studying in four different high school types (Anatolian High School, Science High School, Industrial Vocational High School, Imam Hatip High School) in Ordu city centre. The data of the study were collected with ‘Social Media Addiction Scale’, ‘Life Satisfaction Scale’ and ‘Physical Activity Short Questionnaire Scale’. Descriptive statistics and then kurtosis and skewness values and normality analyses of the data set were performed in SPSS 26.0 programme. Since it was determined that the distribution was normal, independent sample t test, one-way analysis of variance (ANOVA) and LSD test from post hoc tests, Pearson correlation test was used in the relationship between scale scores. The results were interpreted according to 0.001 and 0.005 significance levels. The results of the study showed the relationships of gender, income level, school types, grade level variables on students' social media addiction, life satisfaction and physical activity levels. It was found that male students obtained more positive results with severe physical activity and social media addiction, while female students showed more positive results with moderate physical activity. According to the income level, it was determined that the tendency of the low income group on social media addiction was high, but the middle income group gave more positive results in terms of life satisfaction. Among the school types, it was observed that the social media addiction and life satisfaction scores of Industrial Vocational High School students were higher than Imam Hatip High School students, but there was no significant difference in physical activity levels. According to the grade level variable, no significant relationship was found between social media addiction, life satisfaction and physical activity levels. These findings provide an important perspective to understand the effects of different variables on students' social media use, life satisfaction and physical activity.