This article unpacks the ideology of "cosmopolitan leadership," a leadership theory that has surfaced from a qualitative study that examines the comparative analysis of global citizenship education (GCE) in two primary schools: one international school in Singapore and an independent school in Australia. This article unpacks the idea of "cosmopolitan leadership" and the features of this distinctive form of leadership in institutionalizing GCE in the respective contexts and schools. School leaders in both contexts, took an active role in driving GCE in the school, through the introduction of the international curricular model and by keeping themselves abreast with global curriculum initiatives and through curriculum innovation. These curricula initiatives assisted in the take-up of GCE that enabled the schools to attain their vision of developing global citizens. These were aligned to the schools' as well as national policies and evidenced innovative approaches to address the complexity of contemporary diversity, as well as the demands of the global world. This response was situated in multiple influential contexts, which included the national contexts of the two schools, encompassing the nature and geopolitical positioning of each society, the provision of schooling, the nature of schools and the specific policies governing the two schools, and their market contexts, which have influenced their approaches towards GCE.