Acculturation is the process of psychological and behavioral change that individuals go through during and after intercultural contacts. Social media have become a major space for cross-cultural encounters, and are important venues of socialization for marginalized populations. Intercultural encounters on social media may benefit or detriment the acculturation process, and how marginalized populations make sense of their social media experience is pivotal in this respect. Nonetheless, there is a scarcity of research that examines non-dominant ethnic groups' meaning-making of and digital literacy practices on social media and how these practices relate to acculturation. To fill this research gap, this study collected data through semi-structured interviews with 44 non-dominant ethnic adolescents in Hong Kong. Through the theoretical lens of critical literacy, this study revealed various facets of literacy practices in which these underrepresented adolescents engaged and found that these practices, and the lack thereof, moderated their acculturation process on and beyond social media platforms. The findings suggest that critical digital literacy on social media interaction is critical to non-dominant ethnic groups' acculturation process.