This article examines the evolving dynamics of migration and border management on the island of Ireland before and after Brexit. Using a multidisciplinary approach, the study explores how the Common Travel Area, European Union law, and the Belfast/Good Friday Agreement jointly established a robust migration regime characterized by cooperation and freedom of movement. The operational- and rights-based difficulties of preserving an open border are given special consideration, which includes the possibility of racial profiling in border enforcement, the complexity of administrative procedures, and the differences in immigration and asylum laws in the UK and in Ireland. The article highlights the Republic's anti-immigration sentiment, the growing polarization of public discourse, and Ireland's involvement in the new EU Pact on Asylum and Migration. It finally illustrates the conflict between Ireland's desire to conform to changing European standards and the necessity for bilateral British/Irish cooperation.