This qualitative study investigates how language practices influence the cosmopolitan identity of Chinese students in the UK. Drawing on interviews with undergraduate and postgraduate students, this research explores how English proficiency and attitudes toward English as a global language shape intercultural orientations and identity construction. Students with higher English proficiency and an awareness of its global nature actively engage with local and international communities, fostering openness and cosmopolitan outlooks. In contrast, those with limited language skills or who perceive English as belonging to a specific nation tend to remain within co-national networks, thereby limiting opportunities for intercultural development. The study positions English not only as a communicative medium but as a tool for negotiating cultural boundaries and constructing hybrid identities within globalised contexts. Implications are offered for higher education institutions and language educators to support intercultural competence, identity formation, and meaningful engagement with linguistic and cultural diversity among international students.