This article examines international English-medium students' language aspirations in relation to social mobility as they are studying in a (Mandarin) Chinese-dominant context. It focuses specifically on Vietnamese students in Taiwan and their perspectives on how English and Chinese are related to their present and future life opportunities. Data were obtained from interviews with students from five different Taiwanese universities. Findings suggest that for these students, English and Chinese were highly mobile languages, which could provide them with the possibility to mobilise across imagined geographical, cultural, educational, work and peer communities of lower and higher scales. Both languages were, as a result, seen by them as a vehicle for their trans-contextual Anglo-Sino social mobility. Their imagination about mobility opportunities associated with the languages, however, may not always be achieved. Implications for supporting international students to enhance their multilingual skills and to contextualise the question of language competence in relation to mobility are then suggested.