Individuals with autism-spectrum disorders (ASD) experience high rates of social anxiety disorder (SAD). This study will investigate SAD in adults with ASD, and will develop and pilot a cognitive behaviour therapy (CBT) intervention. A mixed methods approach will be used, comprising qualitative and quantitative methods. Expected outcomes include a potentially effective targeted intervention for individuals with ASD who are socially anxious. The findings will inform the design of formulation-based and personalised CBT interventions for individuals with ASD.