In an era of globalization, social demands for fostering global citizenship are increasing. Global citizens are those who have a critical understanding of interconnectedness, share values of responsibility, have respect for differences, and commit themselves to action. Global citizenship education has recently emerged as a prominent issue in Korea, a nation faced with the inflow of immigrants and international pushing for global citizenship education such as the Sustainable Development Goals. Development nongovernmental organizations have taken up the role of delivering global citizenship education. It is necessary to examine how development nongovernmental organizations' pedagogic legitimacy has been constructed and exercised in the context of Korea. This article critically discusses development nongovernmental organizations' roles in global citizenship education and suggests some improvements in the areas of 'effectiveness and expertise, contextualization, and greater attention to human rights and action for social justice' to be an alternative to the state-led global citizenship education, which is characterized as assimilation model and 'us and them' rhetoric.