The current research aims to examine the roles of perceived social support, coping, and loneliness when predicting the Internet addiction in adolescents. The research participants included 300 high school students, with an average age of 16.49 and SD = 1.27, attending schools in a city in Southeastern Anatolian Region during 2015-2016 academic years. Participant adolescents included 180 females (60%) and 120 males (40%). Data collection was conducted through Short Form of Young's Internet Addiction Test, Revised Form of Multi-Dimensional Perceived Social Support Scale, Coping Scale for Children and Youth, and the UCLA Loneliness Scale-Short-Form. Descriptive statistics, Pearson Correlation Coefficient, and Multiple Linear Regression Analysis were used to analyze the research data. Research findings showed that perceived social support from significant other support, loneliness, and cognitive avoidance and problem solving among coping strategies significantly predicted Internet addiction. Family support and friend support as sub-dimensions of perceived social support and assistance seeking and behavioral avoidance among coping strategies were not found to predict Internet addiction. Research findings were discussed based on the relevant literature, interpreted, and suggestions for researchers were put forward.