Social anxiety disorder (SAD) is characterized by marked and persistent fear in social situations in which one may be exposed and/or anticipates being exposed to external evaluation and in which embarrassment/humiliation may occur. Acceptance and Commitment Therapy (ACT) has been showing promising results in several disorders, including adult SAD. Considering this evidence and given that adolescence is typically the age of onset for SAD, we developed the ACT@TeenSAD, which is a manualized approach to adolescent SAD delivered via videoconference. It encompasses 10 weekly, 90-minute sessions targeting core pathological processes and fostering higher levels of psychological flexibility; it also includes two booster sessions. The current work illustrates the case conceptualization and therapeutic trajectory of a 17-year-old adolescent (Josie; pseudonym) with a 5-year history of SAD that underwent the ACT@TeenSAD. During the course of the intervention, Josie found purpose and learned life skills to cope with adversity, especially in socially relevant situations. This aligns with the pre- to post-intervention progress shown by Josie (using the Reliable Change Index), particularly in measures assessing acceptance, psychological inflexibility, and self-reported social anxiety. Josie’s case study gives preliminary evidence of the acceptability and feasibility of the ACT@TeenSAD, making it a helpful tool for therapists to become familiarized with. The current work also discusses the limitations of the intervention and presents practical challenges and suggestions thought to be useful for therapists.