The purpose of this chapter is to discuss and analyse the interplay of potentially racist, common sense, and anti-racist understandings around and between ‘new migrant’ and ‘indigenous’ students and teachers in one Irish post-primary school. Taking inspiration from Rizvi (1993), this focus serves as a means of being vigilant to the mobility and multi-faceted nature of both overtly racist ideas and well-intentioned actions that may have racist effects. The first section of the chapter discusses national and international research on institutional racism, focusing on schools in particular. It notes how, despite decades of research evidence of institutional racism, official ‘intercultural’ and ‘anti-racist’ stances in institutions can constantly become diluted to racist effect, both as a result of wider state measures and shifting, exclusionary meaning making. School marginalisation is often rendered through ‘common sense’understandings about immigration, citizenship and educational participation in schools. It is repeatedly crystallized through the rendering of students in racialised achievement hierarchies internationally.