This study investigated the associations between personality traits, based on the Big Five model, and addictive behaviors to different online activities among adolescents. A sample of 920 participants was recruited from four secondary schools in different districts using random cluster sampling. A structured questionnaire, including demographic information, internet usage pattern, the Internet Addiction Test, the Game Addiction Scale, the Bergen Facebook Addiction Scale - Revised, and the Big Five Inventory, was administered to each participant. The results demonstrated a significant difference in personality traits for addictive behaviors related to different online activities. Specifically, higher neuroticism (β=0.15, p<0.001) and less conscientiousness (β=0.12, p<0.001) displayed significant associations with internet addiction in general; less conscientiousness (β=0.09, p<0.01) and low openness (β=0.06, p<0.05) were significantly associated with gaming addiction; and neuroticism (β=0.15, p<0.001) and extraversion (β=0.10, p<0.01) were significantly associated with social networking addiction. Our findings may provide a better understanding of the etiopathology of internet-related addictive behaviors and have implications for psychoeducation and psychotherapy programs.