Study aim: To investigate the effectiveness of an Acceptance and Commitment Therapy-based (ACT) educational intervention on improving social skills and reducing social anxiety in 14-18-year-old language learners Design: A randomized controlled clinical trial with parallel groups, not blinded, without placebo, on 30 participants. A random number table was used to allocate participants to the two groups. Settings and conduct: Language learners aged 14 to 18 years attending English language institutes in Choghadak city who are screened during the study will be enrolled if eligible and randomly allocated to intervention and control groups using a random number table. This study will not be blinded, meaning participants, the intervention provider, and the data analyst will be aware of group assignment. Participants/Inclusion and exclusion criteria: Inclusion criteria: Age 14–18 years; enrolled in English language institutes; score below cut-off on Matson Social Skills Questionnaire; score above mean on Connor Social Phobia Inventory (SPIN); written informed consent from participant and parent. Exclusion criteria: Severe psychiatric disorder requiring urgent/pharmacological intervention; prior ACT training; concurrent participation in other psychological interventions. Intervention groups: Experimental group: will receive an Acceptance and Commitment Therapy-based educational intervention in 8 weekly 90-minute group sessions. Control group: will receive no intervention Main outcome variables: Social skills; social anxiety