Within the rise of social networking sites, Facebook has gained a huge amount of popularity and Facebook has been matched with an expanding body of research. Nevertheless, research examining the complex relationships between Facebook addiction and well-being is still insufficient. Previous studies have focused on the direct relationships between Facebook addiction, shyness, loneliness, and subjective well-being. However, no empirical study has dealt with the mediating effect of shyness and loneliness on the relationship between Facebook addiction and subjective well-being. Thus, the present study has examined whether shyness and loneliness mediated the relationship between Facebook addiction and subjective well-being. Our theoretical model was tested using data collected from 280 Turkish university students. Participants completed the Bergen Facebook Addiction Scale, the Satisfaction with Life Scale, the Positive and Negative Affect Schedule, the Shyness Scale, and the UCLA Loneliness Scale. The hypothesized model was tested using structural equation modeling and bootstrapping. Structural equation modeling results provide evidence of indirect effects of Facebook addiction on subjective well-being fully mediated by shyness and loneliness. Bootstrapping showed that Facebook addiction exerted a significant indirect effect on subjective well-being via shyness and loneliness. The findings emphasized the role of youth shyness and loneliness in explaining the relationship between Facebook addiction and subjective well-being. Limitations, implications, and future directions were discussed.