The proposed ProBACT (Promoting Prosocial Bystander Actions) project focuses on examining non-refugee youth’s bystander responses to intergroup bullying of refugee youth in Turkey. Bridging developmental and intergroup processes, the ProBACT project aims to establish their interplay to promote prosocial bystander responses across two studies. Study 1 will examine social-cognitive (justice sensitivity, theory of mind, self-efficacy, and critical consciousness) and intergroup related factors (intergroup contact, perceived peer and parental norms towards outgroup members, media perceptions about refugees, discriminatory attitudes) in Turkish youth’s bystander responses to intergroup bullying of their Syrian peers through hypothetical scenarios. By extending Study 1, Study 2 will test the effectiveness of a novel intervention program that covers components of intergroup contact, outgroup mentalizing, and role models in promoting youth's prosocial bystander responses to intergroup bullying of refugee peers. The proposed ProBACT project will help to identify the factors that pose a threat to refugee youth's inclusion and wellbeing and to harmonious intergroup relations by combining multiple methodologies. This is an especially timely and important issue based on the evidence demonstrating increasing negative interactions between Turkish and Syrian youth in school contexts. The proposal will advance our understanding of social-cognitive intergroup processes in youth's prosocial bystander responses to intergroup bullying of their refugee peer. Overall, the implications of the ProBACT project will provide a novel understanding of promoting safety, inclusion, and justice in the education system and research that aligns closely with the values of the European Commission.