This is the first empirical study to explore how ethos influences the integration of Newly Arrived Migrant Students (NAMS) into second level schools in the Republic of Ireland and Malta. Drawing on semi-structured interviews with school leaders, teachers, and parents, the article focuses on the role of ethos in the school-led integration practices in two schools - one in Ireland and the other in Malta. Although both are schools with a denominational ethos, the two units of study are located at either end of the European Union, with very different profiles and contexts. Findings suggest that, although expressed differently depending on local circumstances and traditions, for both schools, their ethos is a primary factor in their approach to integrating NAMS. While the study is carried out in Ireland and Malta, it is also of interest to other jurisdictions where schools are faced with increasing numbers of NAMS and growing diversity amongst their student populations.