Objectives: The aims of this study were to examine the effects of group cognitive–behavior therapy (CBT) on improving anxiety symptoms and enhancing personal growth among adolescents at risk of developing anxiety disorders in school settings in Hong Kong. Method: A total of 26 participants received an eight-session CBT group and 20 received treatment as usual in the waitlist control condition. Instruments measuring anxiety symptoms, types of anxiety in children, dysfunctional thoughts, and personal growth were used to assess the changes in severity of anxiety symptoms, dysfunctional thoughts, and personal growth among the participants. Results: A 2 × 2 mixed model analyses of variance were employed, results demonstrated significantly greater improvements in overall anxiety symptoms, generalized anxiety symptoms, and personal growth—use of resources in the participants of the CBT group compared to the control group. Conclusion: Group CBT may potentially improve anxiety symptoms of adolescents in school settings in Hong Kong.