Objective: The purpose of this study was to create a group CBT program for preventing middle school students in a potential risk group for such addiction from becoming addicted to smartphones. Methods: There were 16 participants in this study who were found to be of potential risk group based on the Youth Smartphone Addiction Self-Diagnosis Scale (S scale). Each participant was randomly assigned to either a treatment or control group. The treatment group received eight 60-min sessions of CBT (n = 8), whereas the control group received two 60-min sessions of CBT. The effectiveness of the CBT program was assessed based on the Youth Smartphone Addiction Self-Diagnosis Scale (S scale), Self-Control Scale, and Children’s Assessment of Participation and Enjoyment (CAPE). The Wilcoxon Signed Rank Test was used for validation, as well as to determine the effectiveness of the program. Results: As the experiment results of smartphone addiction show, the adolescents improved in terms of self-control, and were able to participate in everyday activities outside of their mandated school work. Compared to the control group, the test group showed significant improvements in smartphone use, self-control, and participation in daily activities. Conclusion: As a result, it will be possible to provide a variety of occupational therapy interventions and expect positive effects on preventing smartphone addiction in middle school students.