Background: Social anxiety disorder is common and typically starts in childhood or adolescence. Cognitive Therapy for Social Anxiety Disorder (CT-SAD) in adults is a well-established treatment that shows strong evidence of differential effectiveness when compared to other active treatments. In contrast, CBT approaches to social anxiety in young people have yet to demonstrate differential effectiveness and there is some evidence that young people with social anxiety disorder respond less well than those with other anxiety disorders. Aims: To adapt CT-SAD for use with adolescents and conduct a pilot case series. Method: Five adolescents, aged 11–17 years, with a primary DSM-5 diagnosis of social anxiety disorder received a course of CT-SAD adapted for adolescents. Standardized clinical interview and questionnaire assessments were conducted at pre and posttreatment, and 2 to 3-month follow-up. Results: All five participants reported severe social anxiety at baseline and achieved remission by the end of treatment. Significant improvements were also observed in general anxiety, depression, concentration in the classroom, and putative process measures (social anxiety related thoughts, beliefs and safety behaviours). Conclusions: An adapted form of CT-SAD shows promise as a treatment for adolescents.