Background: Social anxiety disorder (SAD) is a common and chronic mental health condition. Given the significant prevalence and impairment caused by SAD, it is important to investigate novel ways to improve the efficacy of cognitive behavioural therapy (CBT) for SAD. One approach may be to provide CBT in an accelerated fashion, which involves multiple sessions per week. Such accelerated treatments have been shown to be effective in other anxiety disorders, but in SAD this accelerated treatment has only been studied in a group treatment format. Aims: The aim of this study was to provide a preliminary investigation of the efficacy of individual accelerated CBT (aCBT) in the treatment of SAD. Method: The studied utilized an open trial design. Seventeen participants commenced the treatment, which consisted of 12 sessions delivered over 4 weeks. Results: The results indicated that participants obtained moderate to large effect sizes on measures of SAD at post-treatment (range d = 0.76–0.92) and 3-month follow-up (range d = 1.31–1.79). In addition, at post-treatment, 59% of participants no longer met criteria for SAD, and this number increased to 71% at 3-month follow-up. Conclusions: The results provide preliminary evidence to suggest that individual aCBT may be an important treatment option for individuals with SAD.