The relationship between global citizenship identity and actions remains an unsettled issue. In this article we use the PISA 2018 survey to explore whether global citizenship identity is associated with a greater likelihood of engaging in ‘globally minded’ practices among young Australians. Descriptive analysis reveals that self-reported global citizenship identity is associated with higher levels of moral cosmopolitanism, more so than with greater intercultural values or with more positive attitudes to immigrants. However, this self-declared identity does not necessarily translate into cosmopolitan action. Statistical modelling shows that, in the Australian context, global citizenship knowledge, values and identity account for a limited proportion of differences in self-reported cosmopolitan action. We argue that a sociological theory of practice helps explain these results. We conclude by highlighting future research opportunities to better understand the social determinants of global citizenship practices, including by exploring out-of-school socialisation and a broader range of cosmopolitan practices.