This study examined the mediating effects of Facebook addiction on the relationship between subjective vitality and subjective happiness. 297 university students (157 women, 140 men; M age = 20.1 yr., SD = 1.3) were administered the Facebook Addiction Scale, the Subjective Vitality Scale, and the Subjective Happiness Scale. Hierarchical regression analysis showed that Facebook addiction partially mediated the relationship between subjective vitality and subjective happiness.