During the early twentieth century in the United States and Australia, Italian and Greek migrants, along with other people from the Mediterranean region, were often labelled as ‘dirty dagoes’. The term ‘dago’ was a derogatory and prejudicial racial slur that situated Italian and Greek migrants as precarious racial inclusions within each nation. Drawing on historical studies on whiteness and migration, this chapter explores the origin, use and contested meaning of the slur dago, as well as how the use of the term was discussed by Greek and Italian migrants in the pages of popular presses and periodicals. It will be revealed that dago was a slur that had a transnational circulation and that its prejudicial connotations mediated how Italian and Greek migrants were racialized, and racialized themselves, in the public sphere. By transnationalizing the history of dago, this analysis extends the geographical terrain of migrant racialisation, while also revealing that the routine uses of the slur generated migrant-specific articulations of difference, belonging and solidarity.