This paper explores how discourses of national identity are managed in one of Norway’s core institutions – the educational system. As Norway changed into a multi-ethnic society, classrooms became a central arena for individuals with different religious and ethnic backgrounds to meet. How boundaries of ‘Norwegianness’ are managed in the classroom is therefore of importance. Based on a thematic analysis of observations of classroom lessons and interviews with teachers in schools in Oslo, I argue that teachers navigate between several different yet overlapping discourses of 'being Norwegian'. Using the theoretical framework of bright and blurred boundaries and different understandings of ‘Norwegianness’, I show how teachers manage different discourses rooted in citizenship, cultural traditions, values, ethnic boundaries or Whiteness. These discourses can be activated simultaneously in society and in the classroom. However, the Norwegian school system’s core value of equality and inclusiveness gives precedence to the discourse based on citizenship. To manage the other discourses, teachers use different strategies when addressing boundaries along different dimensions of national belonging.