In this theoretical article, I argue that postcolonial and decolonial theories offer critical conceptualizations and important insights for democratic citizenship education. Starting with the concept of agonism, I explore how postcolonial and decolonial perspectives both build upon and challenge notions of radical democracy. I argue that both perspectives provide interesting starting points for critical thinking, an essential part of democratic citizenship education. The perspectives point toward a profound problematization and historicization of democracy as a concept, as a system of governance through questioning the nation-state, and as an ideal to valorize societies. Despite their similarities, the two perspectives suggest slightly different approaches to education. The postcolonial perspective presents a critical and constructive approach that aims to deconstruct Enlightenment ideas while using them as a foundation for promoting social justice. The decolonial perspective highlights the inherent connection between coloniality and democracy and emphasizes the need for politics and practices of refusal.